I eventually succeeded in withdrawing my money from Germany by using the credit card and would like to share my experience and knowledge I acquired in the process. Perhaps it will be useful for others. Maybe someone will need to withdraw money from a credit card after reaching its cash withdrawal limit and will find my post useful.
My first attempt was to buy bitcoins by using the credit card. I registered on one of the websites offering bitcoins, passed ID verification, but got an error message when I tried to pay by my credit card. I contacted the support team of the website and was told that my bank had declined the transaction. I checked in my online banking that my credit card was not charged.
Then I was able to recharge my mobile and buy Skype credit by using the credit card, and this confirmed that my credit card was still active.
Then I tried paysend.com, which offers instant money transfers from one credit card to any other one. A relative of mine agreed to cooperate and gave me his credit card details, so I tried to transfer money to his credit card from my credit card by using that website, but again got an error message. And again I was told by the support team of the website that my bank had declined the transaction. And, again, I checked in my online banking that my credit card was not charged.
Then I learned that transactions via Paysend are counted as cash advance, so I cannot use that website if the cash withdrawal limit has been reached.
Then I read on the Internet that buying bitcoins by using a credit card counts as cash advance either, so it became clear why I had been unable to buy bitcoins.
Then I found a partial solution. I knew I would have to travel in a couple of months, but I did not know the exact date. I called an air company (Aeroflot) and learned from them that I could buy an air ticket by a credit card and later change the flight by paying a small fee and the price difference by cash in a company office. Thus the initial purchase is like buying a credit. They said it is no problem if my credit card gets blocked shorty after the initial purchase. They emphasized, however, that if I wanted to cancel my trip and get a refund, they would be unable to refund my money because they can make a refund only to the credit card from which the purchase was made.
I decided to use this opportunity and purchased an air ticket for about 200 Euro, thereby reducing the amount of money left in Germany from about 500 Euro to about 300 Euro. And it is quite possible that I will not even need to change the flight.
Someone told me another solution: To recharge a mobile SIM card by using the credit card and later ask the mobile operator to terminate the SIM card and pay me the balance. He told me it works in my country, although I would have to wait for months to get my money.
He also told me that in my country (Russia) I can get cash from a mobile SIM card balance even without terminating the SIM card. He said that to do this, I can buy Webmoney WMR from a SIM card balance and then exchange WMR to cash.
But I judged that it is too complicated and effort-consuming. I did not have any WMR wallet and did not have any experience with WMR. I judged that the risk of my German bank refusing to return me the remaining 300 Euro was not enough to warrant going through the hassle of dealing with WMR, although I got pretty convinced that the method would work.
On Sunday evening my credit card was still active, so I decided to try to withdraw cash from an ATM on Monday early morning before the start of the German bank working hours, in the hope that the problem was a weekly, not monthly, cash withdrawal limit and that the bank officer would block my credit card only after the start of his working hours.
And it worked! I withdrew everything but 50 Euro. I left 50 Euro in the German bank on purpose, to cover all possible account closing fees and ensure I would not owe anything.
Shorty after the start of the German bank working hours, the bank officer blocked my credit card and sent me a notification email about that. I had withdrawn my money just in time!
By the way, I was not charged any currency exchange fee when I withdrew cash from the credit card, because I used an ATM that allows withdrawing euros. In my online banking, I saw that the total fee for withdrawing cash from the credit card was just about 3%.
So here is the summary of what I learned from my experience of working around the credit card cash withdrawal limit:
In addition to its credit limit, a credit card has a daily, weekly, and possibly monthly cash withdrawal limit. This means that if it has been a few days in a row that you cannot withdraw cash, you may be able to withdraw cash next calendar week and do not necessarily need to wait for the next calendar month.
Websites offering instant transfers to other credit cards or offering buying bitcoins by a credit card will not help, because such transactions are classified as cash advance. They will be declined by the bank if the cash withdrawal limit has been reached.
You can buy "an air company credit" by booking a ticket that you can later change for another one. You can pay the re-booking fee and the price difference by cash in an airline office. However, you have to check in advance that this method will work with the air company of your choice.
There may be ways of using a mobile SIM card as a vehicle of getting cash from a credit card whose cash withdrawal limit has been reached. In my experience, I was able to recharge my mobile from my credit card despite that the cash withdrawal limit had been reached. If you have a Russian mobile SIM card, you apparently can get cash from it via WMR, a Webmoney virtual currency. The process, however, is complicated, and considerable fees and losses on exchange rates RUB/WMR are to be expected. I also read on the Internet that you can buy bitcoins directly from a mobile SIM card, depending on the country.
To conclude, I can say that if you have reached a cash withdrawal limit of your credit card, you may still be able to get money from it.