Hi! I'm Eric, an email expert who's been paired with you through JustAnswer.com. I'm reviewing your question now, and will return w/ an answer soon!
It does, I'm afraid, sound like you've fallen victim to a scam. Can you tell me whether your computer is working presently?
I received your request for Remote Assistance, but there seems to be a payment-related issue. Until our customer service team resolves that, I will continue to offer you some options for self-service.
To start, I'll ask you to download and install this free anti-malware program: Malwarebytes
Once installed, please run the program and remove any "bad" files it finds. If you would, kindly let me know the scan results. At that point, we will circle back around to answering your initial question.