OMG not again, O2 "service"

Sorry to be kvetching again, some things I just have to air. It's O2 again, my mobile phone provider. If I wrote the whole sorry story of the hour of my life wasted, it'd be as long a post as the last one about them. Instead suffice it to say that I get a text that my credit card has expired. The number in the text was out of date! I got their main number. Which had lots of menus, but no way to change the card details, and no way to get to talk to a human!!

I tried the web site. Impregnable. Many, many, many pages and links and menus, but 17 years of WWW experience did not help me find a place to change my payment details. Do they want to get their money? (In the middle of it, my login did not work, so I had get that changed to what I'm sure it was already.)

I got an chat advisor. After several minutes of trying to understand what I wanted (!) he gave me a short number to call if I'm to change my payment details. 

... I called that number. And again got their main menu, with no way of reaching a human or give my details. I just gave up for today, I can't handle it, they've defeated me. 

These days my temper has evened out, I don't often get mad at people. But messed computer software and bureaucrazies (hehe) can still give me the Donald Duck thundercloud above my head.

update: After more searching and clicking around, I finally found some info which hints that I'm using Google Wallet to pay them, lord knows why. And since I updated my info there yesterday, I'll assume all is OK.