Vodacom's customer care amounts to customer abuse

I’ve been an unproblematic, profitable contract customer of Vodacom for 18 years. I’ve been trying unsuccessfully since 12 Apr to resolve a complaint about a price increase on my contract (of which I was notified via uninformative SMS on 29 Mar, and which I’ve never experienced before). I’ve spoken to six different people by now, and been misunderstood by each person except the first person in the Vodacom shop where I started out – misunderstood deliberately, as I see it. Vodacom seems to be engaging in “blocking behaviour”, by providing only one communication channel (phone) to shockingly *********** and unauthorised front line staff. I shall not provide the details of my complaint for the seventh time here, because I expect that Vodacom will somehow manage to identify a competent manager who can address my complaint with the competence and courtesy one would expect from a company which professes to “care” about customers. Should this report not have the desired effect, I will take more drastic action, to ensure that I am treated fairly.