Xbox Game Pass Ultimate Code

When I enter the code (14 day free trial), it takes me to the payment method to choose and confirm and when i confirm it starts buffering and then it says that something happened on their end and to try a different time, but i have been trying for the
last week, and it still does not let me so i dont know what to do, i have also tried to do it on the website and on my xbox and it still does not work.

:)