Yes, it's a scam. Specifically, a refund / overpayment scam.
The gist is that supposedly, a fraudulent order of an expensive item has been made on your Amazon account, but don't worry, you will be getting the money back. You will be instructed to give them access to your computer using a remote access tool, although they will call it "logging into our secure refund server".
You will also be asked to log into your online bank, so you can later verify that you have received the money. This is also done so that the scammer can assess how much money they can scam out of you. The scammer will black out your screen so they can quickly edit the html to make it look like you have received your money back, but they won't show it to you at this stage, because of what's about to happen next.
The scammer will now open up a simple command window that is supposed to be the "secure refund server" but is of course just typed into by the scammer. They will instruct you to enter the amount of the refund, to which they will quickly add a couple of zeroes, making it look like you did something wrong.
Now the scammer is in tears. You didn't receive $300, you've received $30000! They will ask you to check your online banking (of which they edited the html to fake having received the money). Their job is on the line because of your mistake! Please, will you send the extra money back to them? But not as a simple transfer, no, you're instructed to withdraw cash from your bank or to buy Amazon giftcards, then ship them (to what likely is a money mule).
Since they know banks are aware of this type of scam, they will even instruct you what to say, that you're buying giftcards for your grandchildren, or that you're withdrawing cash as a loan to your grandchild who wants to start their own beautysalon. They also have elaborate instructions on how to send it to avoid detection, such as using a thick book and putting in bills every couple of pages.
Another refund method is buying gift cards and not sending them, but just reading off the numbers so they can cash them in online. Whatever method is used, it's set up to be irreversible and as untraceable as possible.
If you want to see this play out in real life, there are several YouTube channels such as KitBoga and Rinoa Poison that try to engage these scammers and keep them occupied as long as possible to waste their time, and other channels such as ScammerPayback and Scam Baiter that try to actively harm and disrupt the scammer's operations. Of course, they do so well prepared, using a computer running a virtual machine, so that scammers can do no harm whatsoever; scammers have been known (as can be seen in some of the videos) to lash out and try to cripple their victims' computers by removing crucial files.
TL;DR:
There never was a fraudulent order on your Amazon account, there never will be an actual refund to your bank account, and you will be out any money that you'll send them.