12 year old Discovery Health profile can't be reset or deleted

This is actually for Discovery as a company, but related to my Discovery Health profile. I was a member of Discovery Health more than 12 years ago, and had registered with my company email address and previous cell no. The company has since closed down and I created a Gmail account and changed my cell no over the years. I ceased to be a member of Discovery Health as well. Now, 12 years later I am invited to join Discovery Bank. Only problem is, no way to register. I don't remember a 12 year old logon name, let alone my password. When I try to reset, it asks me for an email address or password,then checks against the ID no the system has on record. When I enter my Gmail address, I get an error. When I enter my current cell no, I get an error. Can you believe that NO ONE at the call centre can assist me? I am told to reset my details via the Discovery website! I can't people!! Pathetic people you have to deal with then they spend millions on advertising.