Extremely poor service

I am appalled at the service I have received from Vodacom since I decided to stay with you guys and upgrade my line in March. Was assisted by a lady named C********** from the upgrades and cancellations who sold me a contract for a specific price, only to find out that I would be billed more than R150 more for the contract. The upgrade was then cancelled but I was still billed the incorrect amount regardless of me returning the device. A credit was passed on my account but was returned to my Vodacom account instead of my bank account as requested and specified to the agent. I was then offered a better deal with the same device but then I had an additional line added on my account which I was billed for, so basically I had been signed up for a 2nd contract by the agent. The frustrations I experienced during this period were really depressing as I had to call almost every second day and was promised call back from agents and managers in the upgrades and cancellations department which I never received. I have been placed on hold for more than an hour several times just to have the call dropped and no call back received, had the line cut and been transferred to different departments several times as well. Nobody was taking ownership and accountability for the issues I was facing and I have had a miserable time since deciding to upgrade and stay with Vodacom and the agents I have been dealing with have not made this transition a pleasurable experience and I am dreading the rest of this contract period as I have just been experiencing issues and dealing with casual/unconcerned agents and managers. Today I was rewarded R30 off any purchase at Checkers only for me to use it with my grocery purchases only to be embarrassed as it was invalid and not working. I am extremely dissatisfied with the service that I have received from Vodacom and I am dreading and regretting the upgrade I had done as it is just issue after issue and I am not feeling valued as a paying customer, especially with the amount that I am paying.There should be something done about all the stress and frustrations that I have been put through by Vodacom agents and managers within the retention's department