MTN is a bunch of ******!!!!!!!

Here we go again! This is my 5th complaint on Hello Peter for the same problem and nobody from MTN is bothered to call me and resolve my issue. I am beyond frustrated at this point with this $#$% service provider. It seems to me that the only focus for them is to be better than Vodacom and they forget about customer service. This is my issue again. I sighed an upgrade in May 2018 for an amount of R550. (R499 for the sim only contract and R50 for the device which I had an option to take out). I was billed R1001 in June and there is now a bill due for the same amount for July 2018. It seems that my old handset installment is still active after the consultant told me that the old handset installment will fall away after I upgrade my contract. For the last time, please fix this otherwise I have to involve ICASA in this and I will only pay for what I signed for. You can call me on ********** 866. The cell phone number related to this query is ********** 630.