Fed up with Netstar

More or less 2 years ago I trated vechile BD77HHGP. I contact netstar and they advised me to start a new contact. I thought with thst they will cancel the old one. In fact I asked them ifvthey can transplant the existing device from the old vechile to the new one and the answer was that I start new contract. Then I reveived a sms telling me that the battery of DB77HHGP was removed and with this I discovered that I am still paying for DB77HHGP. I send them an email requesting them to cancel the that contract but still at the end of this month they still deduct the amount. It seems to me that they are dragging their feet just to milk a few bucks from me. I as a consumer think i have the right to cancel any contract that is no longer mine. Thank you. May be you have a better change of getting an answer from them than I. Mr. J H Jansen van Rensburg. vr.m****@gmail.com