Hi SpudGunMcGee,
Thanks for taking the time to contact us via the Community. It's lovely having you on board with us in the Forums. ⭐
We're sorry to hear you're having issues with resetting the password for the sub account. This is something we can certainly help with however this can only be done with the account holder directly.
You've mentioned in your first post that the account is your parents. There will only be one account holder named on the bill. Please get them to contact us directly via the forums by setting up their own profile. Once they've done that, we can then help further.
Thanks,