Vodacom has the worst customer service I have ever experienced

I have been a client of Vodacom for 14 years. 16 months ago, I decided to cancel and move to a service that was cheaper for unlimited calls as Vodacom remains more than double the cost of other services. To retain me, Vodacom offered to nearly match the price of the next highest service (Cell C and Telkom roughly equal). They claimed they could not match it completetly as Vodacom's service is so much better - even though it took nearly a month for them to make this offer after I tried to cancel. They offered me the choice of one or two year contract. I asked for one year, to test it out, and the next day received a message congratulating me on my new 24 month contract. I have spent the last 16 months trying to fix this mistake. Despite endless communications via both email and calls, things just went in circles again and again. Only slight relief was experienced with one team leader at Bytes outsourced to Vodacom, but he is almost impossible to reach. This reached its head last week, when after a mail to that leader resulted in me receiving a call to fix the problem, the person who promised to fix it never got back to me again. I called to cancel my contract, right where I was 16 months ago, and in response the "cancellation" - actually it's a retention - agent, fixed the mistake immediately. However, when they asked if I wish to renew or cancel, they are unable to promise me any improvement in service, offer me any compensation for the enormous time and energy wasted the past 16 months on failing to get a simple thing resolved, or fix the other simple problem which is that I as a RED VIP client am supposed to have a special expedited customer service when I call 111 - ha ha ha ha ha. Who at Vodacom can actually provide a decent client experience besides Morne Nel of BYTES? Why is it impossible to fix the simplest problem? Probably all the other providers are equally lousy, but at least I might as well find out for myself hey?