Hello, @Cohen-Ponsford
Welcome to the Rogers Community Forums!
I can imagine how frustrating it is has been trying to get your username changed only to keep running into this error.
It sounds like there could be an issue with your MyRogers profile that is creating this error. Can you confirm why you are trying to change the username?
If it is in someone else's name, you can register for a new MyRogers profile using the correct email address. Once done, simply unlink your account numbers from the current profile and then link the account numbers to your new profile.
Let us know if you run into any issues.
RogersTony