MTN upgrade

In September i was contacted by an external MTN agent and asked if i want to upgrade. I agreed on the upgrade as the offering was good. So the first month come did not get what i was offered on the contract. I then called MTN to request to cancel the upgrade and offer me a better deal that will work for me. In November, MTN agent called me to perform an upgrade. The agent advised me that the previous upgrade will be reversed and a new contract will be performed. During the call the agent advised that i will get in total 800 min a month split between on et and off net. Come 12 December not all the agreed minutes are loaded on to my account. When i received my invoice, i was charged for the free minutes that was allocated and which was suppose to be free. I called MTN retentions department to sort this out with no positive outcome. All they tell me is to log a call which i did and no one followed up on that call that i logged. I have send numerous emails to a person called Renall who advised me that a retentions officer will call me back to resolve this, its been over a month now and no call and no email from anyone at MTN. I have had this contract for over 19 years with MTN and this is by far the first and worst service/experience i have ever received. I think its time to move away from them as it seems to me I'm just a number for them. I hope MTN will call me back as i will not pay this account until this is sorted out and i get what i was told i will get as per contract agreement.