Nicola,
I am so sorry to hear about your experience over the weekend. I work at Adobe, and when I saw your forum post I found that I was having the same problem on my personal account. I reported the issue internally, and I believe it is now resolved (at least it is on my account). Please check on your end by logging into your MyAdobe account and selecting My subscriptions and services. It is likely that you will see a link that says "Manage," "Renew," or "Active." Once you select that link, you should see another link that says "Edit Billing," and you should be able to update your credit card there. I have asked the Customer Support team to contact you directly, but if you don't hear from them, you can feel free to email me (bfink at adobe dot com).
Once again, I am very sorry for the experience you had.
Regards,
Barbie Fink (Adobe Customer Experience Improvement Leader)