When i try to update my payment method im told “Contact Apple Support for more information” any help

 contact iTunes Support. Either use the form or scroll to the bottom of the page in the 2nd link. Follow through the screens to get a chat or telephone option.  

iTunes Support

iTunes Support – world wide

Thanks...

But WHY is this happening? I have not been able to add or update my New Card which had expired! So frustrating...I keep getting message Go to Settings and set up 2 factor identification...which I HAVE DONE!!!

You are welcome. I am a user like you and I am not familiar with Apple's procedures.