You have a virus, it's called a RAT. Remote administrative tool.
It allows the hacker to view/record your webcam, view/record your desktop, access stored passwords, log the keys of what you're inputting, view and access your files, and a ton of other shit you don't want them doing.
First thing on your list is to download an anti-virus program if you don't have one. If the virus isn't detected, then it's encrypted (not detectable by anti-virus). If this is the case - then you're going to need to have a fresh install of your operating system.
After you've got a fresh installation, then focus on getting your money back. Check your card statement and see what's been purchased. Amazon could simply of been the last website they accessed. Figure out which websites have been purchased on, then contact support and hope they'll help you. If they don't, charge back through your bank.
You'll be fine. Just be careful next time. If you need help feel free to message me. I have lots of experience.