Helpppp

I'm on the last part of my student finance application where it asks me for both my parents financial information and I have two options to select.

Online - in the same application form as me
or
Online - after I have completed the student finance application

So with choosing either of them, it then asks my to enter my parents customer reference number to login but the problem is they don't remember it. So I clicked on forgot customer reference and it asks for email address and security answer, they don't even remember that either. So then I tried to register for a customer reference and enter their personal details, but it says you already are registered.

So there is no way to register for a new customer reference number or retrieve it as they have forgotten their email and security answer. What can be done?