Hey galambo, welcome to the board!
I'm not sure if I agree with everything you say, but I must say I'm sorry to hear of the 12K taken out of your account out of nowhere! A real kick in the nuts I have to say.
If your account lays dormant for three years, it's wiped out. If they find a mistake made more than three years ago, then it's ok for them to fix it now. Yep, kick in the nuts.