How to unlock an Apple ID through e-mail?

My AppleID was just registered and used on iCloud -- but not by myself. Perhaps a Christmas present erroneously associated with my e-mail, or maybe not. Could be malicious. Either way I want to secure the account which has been hijacked. As it's a web-app, I asked on webapps: https://webapps.stackexchange.com/q/123423/24327 then found I was able to gain control of a "fake" type, spam-trap, account: https://webapps.stackexchange.com/q/123424/24327 So I also asked on the apple forum: https://discussions.apple.com/thread/250043907 Not looking to spam the internet, but this is annoying and moderately concerning. So, asking apple experts here: How do I gain access to the account associated with my e-mail not having knowledge of the associated phone number? Because I'm not able to proceed past that point.