Geveuvu58 Unfortunately this is a "Customer help customers" community. That means, we don't have access to your personal account at Swisscom and especially, we don't have any possibility to change your payment details. I strongly recommend to contact Swisscom directly via one the different ways:
The best would be to follow this link to find the correct contact form:
https://www.swisscom.ch/en/residential/help/contact.html#rechnungen-und-bezahlen/bezahlen
there:
or call the Hotline from abroad:
[+41 62 286 12 12](tel:0041622861212)