I recently moved to Plusnet from Virgin, taking my existing mobile number with me. During the changeover I was allocated a temporary number. The changeover is now complete and my phone is working fine...with my old number intact.
However, to login to My Account I have to give a User name or mobile number. The former appears to be an eight digit number ( apparently my account number) and the latter is the temporary mobile number allocated during the changeover. There seems no way of altering these details to anything more memorable..
The plusnet App also comes up headed by that temporary number!