Poor Service

I cancelled my tracker late August 2017 and I received a call from Altech whereby I give them a months notice. I kept receiving sms's and emails telling me that I still owe them money, which is impossible as the unit was paid for up front till December 2017. After numerous calls made by me to figure out what the confusion is it was brought to my attention that they claimed I had a Technician call -out, which was incorrect. I took my vehicle to Altech itself for the disconnection of the unit. Again I was informed that they will make a debit order to my account for the remainder of the money. That still didn't happen. Today I received a call from the call center saying that they struggle to pick up my vehicle whilst conducting a test! How come they want to do a test if the unit is cancelled!!!! I explained my story again and I was asked by the agent if he can transfer me to an agent to cancel the unit. How many times do I have to tell the same story? How many times do I have to make phone call after phone call for this issue to be sorted out!