The worst service ever

I was a customer for over a year of ADT. In Oct 2014 I informed ADT about our intended move of property. In Dec 2014, we actually moved and their consultant came to advise us regarding a system for our new property. The whole month of Dec we waited for the installation of our system. Even the request for a daily patrol only happened once or twice but payment was demanded up front without any service being provided. After hours of calls, holding on for 18 min each time, and many promises of managers that will phone back, I requested the cancellation of the contract. In Jan 2015, I was contacted by ADT and Lisa stated that I will be refunded within 15 working days. Now, another dosen of phonecalls later, it seems that nothing has been done yet, and again I must wait for another 15 working days! Will this ever end?