find the actual adt company number in the phone book ... call them and file a formal complant ... go up the chain until you personally talk to the general manager ... they are a corperation and every city answers to a higher up ... at the least the sub contractor will be questioned .... maybe dropped ... do not give up ... keep going up the ladder till you become tired or get satisfaction ...

ps: if they will not do anything request a refund or credit on your monthly bill till the amount is recovered ...
call them every day if you need too ... remember go as high as you can up the corp ladder ...