François B. 6694 ✭✭

@Paulo, yes. I even paid for a mobile add-on with my "internet" credit card.

I was able to add a second card without a problem, although it was when I subscribed to internet (was already subscribed to mobile with a different card). I can select any card when paying for add-ons now.

For some users, retrying later eventually worked. Sadly I don't have a better answer for you, but it might be worth retrying.

I think it's worth it. Things are going well, I didn't have any problems for a while.