I need a way to avoid reseting a WP

So my brother in law got himself a WP (Lumia 820), for simple business use (basically just email and calendar, and not a lot of it).

Knowing nothing of the OS beforehand, a kind salesman in the local carrier store (in Belgium) offered to assist him.

What he did was:

  • make a new live.com account
  • make it ms account on the phone
  • make a new gmail account
  • make the gmail account a parent account, and ms account a child

The reason was that the salesman put 2013 as the year of birth for the new live.com account and when things did not work he got inspirational and went, for whatever reason, to gmail.

So basically he can not use store (not even to update apps or download free apps) because a pop up says that his parent needs to approve. But he does not even know which gmail account is the parent. Or that he even has login info for it.

Is there some kind of workaround not involving a reset? Or will I have to fix it for him the hard way? I was so getting used to not having to manage my family members phones past the initial setup once most of them switched to WP :|