Unavailable process payment , please try later

Hey

im having trouble updating and purchsing on my App Store , it goes straight to my password to type in and it's fine and then goes to my bank details and my bank details and it said declined but when I did it again fine it said above (uniaviable payment processing )Any solutions , is it them as in Apple Because my bank card is still in date and still useable ? And if it's them it's okay , it's just very annoying as I haven't had this problem at all before ..

help please

beverley