On the general Microsoft account issue, my Skype account I had for 10+ years also became inaccessable after a random criminal linked their Microsoft account to my Skype account to make fraudulent transactions. After trying to get my skype account back using the account recovery form, I realized that even though I should have had enough answers to successfully recover the account that it was failing probably because all the answers were now being checked against the criminal’s Microsoft account instead of my Skype account.
No amount of customer support chatting or Microsoft supoort calling could get that account back, or even get someone to investigate the fraud. I suppose that Skype makes money off these transactions so why bother to stop it.