Unfair Selling of product and post barriers when can cancelling

I had a tracker fitted in my car at the dealership in 2016 when I bought it. I received a call from Netstar last week offering an upgrade on my tracking device. I advised the lady the I have been with them for 9 years and only now they offering an upgrade. I asked her to check how long I have been a customer not being aware that this is not my current tracker company. She played along and did not disclose that I don't have any new products with them because she wanted a sale. When the fitment guy installed the tracker and removed the old one only then I received a call from my own tracking company asking about the removed unit. I called Netstar to cancel, they referred me to the third party that sold the unit and told me about a cancellation fee which I was not told about on the initial call as it was an upgrade. They advised that the turn around time is 24 hours and they have to listen to the recording. 24 hours has passed by and this tracker does not want to cancel. They are giving me a hard time to cancel, they send me the contract on the day of cancelling. The contract is written that I am a Mr however I am female and my car model is unknown. They sold this policy with false pretend and wrote my information correctly. Please cancel this ASAP as I want to go back to my initial company Tracker SA.