Good day and welcome,
Just on the topic, you are able to log a call using the link below, the support team should be able to engage the data protection team to assist you in verifying ownership. If you have another tenant, you could also use https://support.microsoft.com/en-us/topic/global-customer-service-phone-numbers-c0389ade-5640-e588-8b0e-28de8afeb3f2
https://portal.azure.com/#blade/Microsoft_Azure_Support/HelpAndSupportBlade/overview
Please accept the answer if this information was informative and assisted you.
Regards
M