They feel nothing for their long-term customers - Will never use them again

I have always had great dealings with Vodacom, until my last. On 26 November 2018 I got a call from Vodacom offering me a deal on a wifi router and ON TOP OF THAT I will receive discount because I've been with the company for more than 10 years. We talked for 18 mins in which I confirmed with her numerous times that I will receive the discount. By the end of December I noticed that the monthly payment was more than anticipated; they had not added the discount I was promised. Since then, I have opened 2 queries, both of which were closed with absolutely no feedback to me. On both occasion I had to phone, explain my problem from the start and get told that the query was closed. Today was the last phone call and I was told that the query logs the following: Invoice does not show discount (which is the whole problem), call recording requested, query closed. Which means they did not even bother listening to the recording. It is completely unacceptable that Vodacom is taking money that I have not allowed them to have, and ignoring my attempt at rectifying the problem. At this point I am contemplating whether I should just cancel all my contracts if it means I won't need to deal with this any longer.

PS: Your consultants are friendly and helpful and they are not the problem. The problem is the people to whom the issues get escalated.

UPDATE: Almost a month later I have not had any feedback from Vodacom and just paid another wrongful payment. Vodacom - You have lost me as a customer. There is nothing I can do to keep you from *****ing from me, because you clearly don't care. After the last call on 19 Feb I did not even receive a reference number so I can't follow up on it - even though I was profusely promised that they would contact me.