I've not had that happen with a credit card, I have had it happen with a phone bill. I did an online search also, found out it was called "cramming", and fortunately had a great phone customer service person help me out.

I see through a quick search that there is quite the issue with false credit card charges. If you talk with your credit company can you let us know how it goes? Whatever you learn will probably help many readers. Good luck with it all!