ASPIRE ACCOUNT BLOCKED SOMEBODY SPENT 500.00 Ripoff COLUMBUS Georgia

I received a letter saying my account was suspended for unsual activity to call 1-888-576-9432. First I decide to call the number in the back of the card which was different from the letter. I thought was a scam actually.
When I called the customer service number the call was straight to a representative without pressing any number... Strange

I said that the letter said my card is blocked and he said yes for unsual activity and start listing all my activities some matched and than he said was a purchase in bath beyond for 500.00. I said no I did not purchase. He said other charges as well that did not matched... He said I have to fill the afidavit paper to investigate and than they will refund me the money. But I told him I did not use this card online or nobody had acess to the card.

Now I was searching in the internet and I found this site with many complaints and I am really scare and worry. Is that a fraud? They create theses charges so we can pay them and they will never pay me back?
Because if I dont pay 500 dollares I will keep paying finance charges and others monthly untill they solve this case. But in the same time I dont want pay 500.00 and if they will not pay me back?
What I have to do?

F1
Wheaton, Maryland
U.S.A.