Hi there and welcome
It is a scam, and you were not actually hacked. It was a faked message to get you to stress about the issue and want an immediate fix, which is when they can get away with paying such a high price.
I always advise my customers when this happens to contact your credit card asap and indicate it was a fraudulent charge. They will normally reverse this charge for you.
Sometimes this message they put on your computer is hard to get rid of, but it can easily be done if you know how so you can always ask me here.
Or sometimes they call you tell you they have been notified you have a virus or errors, this is another trick which you need to just hang up on.
If you would like any additional information or assistance, please do not hesitate to let me know.
And if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.