Payment

Hi there. I have a very annoying issue that i hope someone can help with . I have been trying for 2 hours to buy a game on the xbox store and i can only get as far as entering my postal code . When i get to that part it tells me it is an invalid format
which is absolutley not correct . I am wondering if anyone knows what to do from here ? I know i am not the only person with this issue so any help would be very much appreiciated! Thank you !

:)