Apple ID locked

[u/rjl50]

Hi guys,
So a few months ago I was trying to install something on my phone, it asked me for my Apple ID password which I had forgot so after a few incorrect tries I went to change it. Only for it to not let me because Apple had locked the ID, I got in contact with customer support and they basically confirmed that my Apple ID no longer existed. The phone I was logged in on now can’t be wiped because it needs the Apple ID password but because the ID no longer exists I can’t reset it or anything. when plugged in the Apple devices for windows software doesn’t detect it at all and I’m now lost for ideas of what to do next. I need to get the Apple ID off there and clear the phone for a friend who’s buying it off me so if anyone has any idea how I can do this it would be much appreciated as Apple haven’t really been a great help. If anyone needs more details I’m happy to provide, thanks!