Pathetic service delivery

I've been with adt 3 months now. Always a struggle. I phoned them to come and move the alarm system which prevoius owners installed. The made a booking for the Thursday. I asked the lady how much will it be to move the alarm system and she rep**** call out fee if R573. I said ok is that to move the system she said yes. The technician came out an hour late. And when he entered he said he doesn't have time to move the system. I said but I made a booking as we are renovating and the boxes will the be in my bathroom. He said he will quote me and come back on Monday. He's quote now suddenly is R1700. When i phoned the call centre I asked to speak to a manager. She said I must wait 20 min then a manager will phone me back. The next day I phoned them to give 20 days notice as I do not get service from them and the call centre is useless. Suddenly a lady phoned me back 5 days later to tell me she'll send me an invoice for cancelation fees of R1700. I said why should I pay for service I'm not getting. So they can brake contracts like they want and when you want to they want to charge you cancelation fees. I told the lady I don't want her invoice she can get a manager to phone me. Still no manager phoned me. They're not even trying to keep their clients. Just I will send a invoice.