Poor service delivery

I have been called by an affiliate company of MTN, Rewards Company. To offer me a contract on my upgrade that was due. I was informed that a recording was made and then I upgraded. I was offered a S9 cell phone with a Samsung gear and R500 voucher that can be retrieved at a Mtn store. I then agreed and the phone was delivered 7 days later, when I then tried to get the Gear and R500 voucher I was told that there is no such deal on my upgrade. I then called the company on 1 October and requested the voice recording. I was told 3 to 5 working days for this investigation. I did not receive any feedback and called again on 8 October to be told same story. I waited and called in again on 12 October and yet again no joy. I spoke to an agent who again advised me about the 3 to 5 working days turn around time. This is absolutely poor service and when I then tried to cancel the contract because they have not met their side of the deal...I was told that I will get feedback on 15 October. This is ridiculous I feel that the service is very poor and I am extremely unhappy regarding this matter!