Email access- post account creation limits

I have not had access to the desired email address for YEARS-  Previous requests for assistance have landed nowhere - I have a third party website account locked behind a @comcast.net email address that I no longer have access to - This account is still being charged via a subscription model. I would very desperately request access to this account, but after days of comms with comcast employees, no accounts can be made or accessed- Please help.