Imageshack.com review: Credit card

I used Imageshack for a long time now and enjoyed my time on this website. Recently I changed my card and contacted Imageshack customer service and asked them to change my credit card details. Customer service rep told me that he could not do that because there was something wrong with my new card. I called my bank and they said that there was nothing wrong. I went back to customer service rep and asked him to try again. Nothing. I have no idea what was going on and what was the problem.