Ignoring e-mails

I am rather sick and tired trying to contact ADT's accounts department in order to get them to sort out the mess that is due to the incompetence in there department. Payments does not reflect, credit notes does not reflect. Trying to sort it out telephonically, I might as well have spoken to a brick wall. Trying to get a response via e-mail was also to no avail. Will definitely be looking for another security company soon.