Have you tried emailing them a bit? It is worth a shot I think: you made a typo (people make them all the time), but you don’t really need to fully authenticate, because you are just making a deletion request anyway (not trying to access the data).
(Also keep in mind, customer service people have to argue with assholes all day long, staying polite but clear but on-target can go a long way. Stick to the topic and never give them an excuse to cut off communication).
Yep. That's how I learned that I need the photo ID with the original date of birth. My last e-mail was asking if there is any other way to delete the account but so far I haven't heard anything.
I think the GP was suggesting, and imo it's a good idea, that you should first ask them to update your birth date saying you entered it incorrectly. Then you can request deletion again and your ID should be accepted.
That was how I initially approached them. I told them I made a mistake with my birth date and asked if there was any way to correct it. They asked me to send a photo ID with my name and birth date, which I assumed was to replace the old date. I then realized they meant the ID had to have the fake date and we went 'round and 'round (and 'round) on that until I gave up on them understanding what I actually wanted to do. Now I'm trying the more direct 'Please help me delete the account.' approach. I'm not hopeful, but you never know!
I think the more direct approach has a good chance. They can’t update your birthday, reasonably IMO, because they would be giving you access to the data after you failed the authentication. But they wouldn’t actually be leaking any info by just deleting the account.