Hello Llathaithauch93
Please kindly note, on this platform you are using a free service at zero cost. People helping here are all volunteering travel experts, spending their leisure time to help others, and this even on sundays.
We are therefore grateful if people ask concrete questions or describe their problem in details. And yes, getting a hello and thank you is appreciated as well.
If you want instant help from a professional, you are welcome to call the CFF Contact Center anytime at 0848 44 66 88 (CHF 0.08/Min, waiting times may occur).
There are so many different payment cards, it would have been helpful to know it is about a bank card. We cannot read your mind.
That said:
If you have an SwissPass account, go to sbb.ch > Login, log in with your username/password and remove your card from your profile and add it again. Do this via the website, not on the SBB Mobile app. From experience, this should solve the issue and was the resolution to others having had the same issue before.
Kind regards,
Roland