Hi munangst24, thank you for reaching out. Is this happening on all browsers, could you please try to clear you cache and cookies to see if that helps?
The exact same thing is happening to me. I have tried multiple times to update my card- the card even works for xfinity/Comcast internet but that problem error happens every time for xfinity mobile. I even called customer service and they tried it on their computer system and same thing. The agent suggested I try other cards- which we did and still the same error in the system with her. Her help was to try again at a later time. I have done so and still no dice. The card that I am trying to update is no more- the bank sent me a new one ( although for the same bank that was previously working just fine for this account) and I am trying to fix this issue before my next payment is due. If you do a google search you will see we are not the only ones who have experienced this issue.
Any help would be appreciated.
Indeed after a few phone calls and a moderate amount of time, techs were able to solve the problem. It was something to do with an error that occurred in the system when I formed the mobile account and the tech was able to go in and fix it. It did require a little bit of persistence on my behalf as it was suggested multiple times that it was the bank rejecting the request due to perceived fraud. I talked twice with the bank and was assured that was not the case. However, the techs were also persistent in trying to find the problem and after a few hours, they did.
Thanks - Stephany