Upgrade cancellation and reimbur*****t

On 29/03/2019 an Summer Mobile agent sold me a package over the phone for iPhone Xr (64GB) @ cost of R689 per month. A few days later Summer Mobile sends the contract through to me with a different cost. I asked them to cancel the deal, as this was not what was agreed on the phone. I have not received the phone and am being charged an amount without the service. I have contact Summer Mobile, MTN Channel Support and the MTN help desk on numerous occassions over the last 7 months. I have a list of reference and escalation reference numbers and am not getting any feedback on this matter. Why does it take over 7 months to cancel this upgrade? I am not going to pay the cancellation fee as this is not fair. I also would like the money paid to date for the contract to be refunded to me.