These companies spin up and shut down with great speed. Best thing to do is to call the credit card company and call them a scam then ask if they can reverse charges. THEN get new cards as most of these sell your CC numbers to others.
KILL THAT CC AS SOON AS POSSIBLE.
As to accessing the company you are right to be concerned. If you aren't sure it's best to factory reset then load your stuff from backups.
My mother in law was on her computer when (this is her description) “a message kept popping up indicating malware” so she clicked which got down a rabbit hole and eventually to TG Tech. They got her to sign an agreement for “computer fixation” charged her over a hundred and supposedly fixed her computer. I can’t find anything on this company. Did find their website tgtech.us, nothing else. Concerned about them accessing her computer. Any body know this company?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic