No response and incorrect information

I have been trying to cancel a contract for the last 3 months, I keep being billed despite not having used the service since I first requested a quote. I paid the fee after paying the full outstanding bill that was also reflecting on the cancellation quote only to be told the quote of R2500 is now R7500 as the device price increased... Would love to know hoe my current contract of 3 years ago now needs to pay for a device I never had (quoted on Macbook13” when the device is an 11”air) queries are closed without response yet my fee is increased and communication methods altered which makes me wonder why I don’t just tell MTN to stick their contract seeing as they can’t even honor the agreements they make with their clients. Don’t think it helps speaking to an agent face to face at a branch as these guys have to wait on the faceless call centre who is has no regard for customers. And don’t bother quoting reference numbers because “your call has been closed” hours on the phone listening to voice prompts and hours in the branch. Waste of time MTN, yet you want more money for no service! Fed up with their *********** manner in dealing with clients.