Your Apple ID is either invalid or not supported.

I had a iPhone 7 with my old account and it got stolen, and I have short term memory loss so I completely forgot to deactivate my account.

Since then, I realised I have old contacts saved to my iCloud that I need to get in contact with.

But for some reason, when I try to login it only says: "This Apple ID is either Invalid or Not Supported".

Could someone from Tech Support please elaborate what this means as I urgently need to recover the photos and contacts saved to my iCloud.