i do not want tracker

I purchased a new vehicle from a dealership , at the point of sale I was told that tracker would contact me and offer me a service and I could choose to continue or not , no call was made to me and the next thing I knew I received a sms welcome to tracker , I immediately called the call centre and spoke to Gladys who was suppose to inform them not to touch my car , that was at dealership. the next day I hear tracker has already put their device in y car , Mellisa Naidoo who last week promised to listen to the calls and respond *** - has bothered tooo , I DO NOT WANT TRACKER , please do not force this one me , I have not signed nor spoken to anyone for this , and yet I have a 36 month contract with them