Appalling Customer Service

I have been trying to log in to our vigin account, but they have introduced s 3 step verification. The email address that the account was set up on doesn't exist anymore. I contacted an agent, who raised an IT ticket and said someone will call you within 48 hours. They didn't. Then I spoke with another agent who asked for letters of the memorable word. This account was set up about a decade ago and we can't even remember setting one. I was then told a letter with the word would be sent to the registered address. It would take 3 days we were told. It didn't arrive, contact another agent who said it would be raised to the senior leadership team and that I would receive the letter within 48 hours. I didn't. This is appalling customer service.