A little bit of context:
- I did some online shopping.
- I added some items in the basket for total amount of 770 and payed online with my card.
- the 770 value transaction was status "pending" on my bank account right after that. It usually takes 3 working days for the bank to actually debit my account
- today (more than 3 days later) I receive the package with the invoice and a message that some of the items from my order were unavailable so they deducted that from the value of my original purchase. Value of the invoice is 680 (770 - the value of the unavailable items)
- I check my account and 680 were debited. Which is the correct amount.
- I do online shopping often enough and this is the first time I see this happened.
Now my question.
How does a pending transaction of 770 gets debited as 680?
Does retailer cancel the initial transaction and start another one? Do they modify the existing one? Is this a special type of transaction? How does it work?