Bad customer service

Cartrack has debited my account twice in July because of the bad experience I have been having with Cartrack for the last 33 months I then decided to reverse the debit order with my bank and they also reversed the other debit order I then called them the consultant advised me that it is still showing as paid I will have to wait I then received a link on the 25th to pay the amount I paid same day but everyday eversince the 25th I have been receiving calls from cartrack about my account being in arrears despite me paying the amount I then requested to pay them the remaining 3 months of my contract so I can be able to cancel the contract but the lady from customer service called me to advise that if I wanna cancel they will charge me cancellation fee but my question is why must I stay with a service provider that treats me as if they doing me a favor by being with them. I sent them proof that my account was paid to Xoliswa Ntsume who promised to come back to me but never came back to me I tried reaching out to her however every call center agent you get through to ask for your ID No and promise that Xoliswa will come back to me. I now understand why they bind you with a 36 months contract and made it difficult for you to cancel its because they know they have very bad service