I didnt know that. Still tat though
Oh dear, the internet is an oracle of knowledge but sometimes the internet takes people down a path that leads to a much bigger problem than the original. Do someone a favour and go back to wherever it was that advised you to default the user and installer codes and let people know it may not work out as desired, it may just stop someone else having the same problem as you now find yourself in.
If the default installer code is not working its probably a different ADT own default installer code, all you can do now is call ADT and take out a contract, or swap it for something that you have control over.