Cant access my old xbox live account. I only know the gamertag but idk the email/phone...

this account was created over 10 years ago when i was a kid and i havnt used it since i played 360 games with my friends pre 2013. i have no idea what email i used. the gamertag is tiindall. i called phone support and they werent able/willing to help me,
apparently the information to the account is encrypted so they cant see it.. iv gone through the online process to no avail. i put alot of time and money into the games on the account so it.... i can send any ID needed to prove my identity if needed.... considering
the amount that ive invested into the account i simply resufe that there isnt a way to help me. the person on the phone said they couldnt give me any info to protect the security of the customer which is fair enough. but I AM the customer. HELP ME

i dont have my old 360 any more so i cant just use it to see the info im looking for. it died a red ring death a long time ago.

:)