Used to have @onetel.com account which onetel ceased supporting and I must have changed...

Used to have @onetel.com account which onetel ceased supporting and I must have changed to current *****@***.com address but that does not recognise password for onetel address. I receive nectar emails at least weekly so they do have my new (*-* years old) address. In March I spent *-* hrs per day for over ** days trying to register as a vulnerable person for home delivery, but that’s impossible without my password and requests for message to reset my password do not result in any message at all from them. A competitor recognised, without us asking, that my husband was ** and offered us priority delivery slots. However I thought I’d try again when there was less pressure and I’m facing the same issues now. I can’t register for ‘Click and Collect’ except if I creat€ a new email identity, which I do not wish to do. All my current telephone attempts bounce back as ‘call failed’. How can I get to a password to let me access them?