Hello, I'm trying to purchase some bus tickets from Megabus.com and can't get their website to accept my US Visa or MasterCard credit cards. Interestingly, their website offers the option of making payment in British Pounds, Euros, or US Dollars. And their payment webpage has a country dropdown list (where I've selected "United States").

I've called my credit card issuers and they swear they're not the ones declining my transaction, and they've even notated my account to expect UK transactions. (I'm only trying to charge £4.50!)

Has anyone experienced similar problems? My credit card billing address is a post office box. Do UK websites expect certain addresses to be entered in a particular manner?

Thanks for any suggestions!