Every standing order payment made merely goes to service the interest on the card balance which is why you never see the balance drop. If you have the funds to pay the balance immedietly in savings, etc, then do so, making sure you cut up the card and close the account. I`m not an advocate of borrowing from peter to pay paul, but think about a personal loan to clear the balance (again making sure that you take a scissors to the card, or you will end up in a worse situation than before!)
In lieu of a credit card, why not use laser? Accepted across the country and you spend the money you have, not money that you will have to pay interest on.