Amex Prepaid Card Complaint

Amex Prepaid card department,

Payroll card Managing, opening, or closing account Oklahoma

I had a prepaid American Express Serve card, and when I called in for help on -/-/2015 for assistance with adding funds, they closed my account. I had $290.00 in cash on the card. They will not give me any information and will not give me my money back. They said I violated the terms of my agreement.? I am not aware calling in for help for a violation. They claim there was suspicious activity on my card. If they 're protecting me, I 'm concerned they will not give me my money back.