Completely unable to make purchases on Web Store/PC client

Hi, I can't make any purchases at all on the web store or in the PC client. I have tried everything:

• Tried at least 4 different payment methods. All of them give various vague errors. (The payment methods are 100% valid; I use them all the time.) I have included screenshots of some of these errors.
• Tried on both web store and in PC client.
• Tried on different devices, cleaned browser data, etc.
• Tried on local network and mobile data.
• Tried with and without VPN.
• Tried changing my location and real name in my EA account. The location is correct and my name matches the name on my payment methods. Checked my birth date (I am not a minor). Checked all other info and settings multiple times and didn't see anything out of the ordinary.

On the PC client, with several payment methods that aren't available in the web store (iDeal, SOFORT) it even gives errors BEFORE I can even initiate the payment process, proving my point that the errors have nothing to do with my payment details.

I CAN make purchases through Google on the Android app. I purchased the 1410 crystal bundle as an experiment and sadly missed out on the Coaxium and 5% bonus. 

The issue is clearly tied to my EA account. Either the payment system is somehow broken for me, or my account is for some reason blocked from making purchases. I wouldn't know why, though.
I never played the app on any unofficial APKs or did any shady stuff, other than link my account to an unofficial app that can open Bronzium ally point data packs (Mhanndalorian bot on Discord). But many people use such tools so I can't imagine that's the problem.

My game is linked to my Google and EA account. My ally code is 514331734.

Thank you for any help. Again, I want to stress that I am 100% certain that the payment methods are working on other websites.

p.s. EA help is infuriatingly unhelpful. I have been in chat since January 23 (3 weeks!) and they haven't provided a single useful response. They reply once every 3-4 days with a single, short message, asking insulting questions like ''have you tried restarting your device?''. It is genuinely infuriating. Sorry for the little rant, but this customer ''service'' is so bad it could make anyone mad.