[Taking American Express for payment on the site]

Hi, been using Fiverr for a couple of years now. We here at our company only use the American Express business card. For some reason Fiver does not take that card for payment anymore. Can I get a reason why this is? Now the boss is saying that I need to find a new site to get jobs done.

thanks
Shelby Lohrman
American Chess Equipment
Wood Expressions