Pathetic service from the retentions department

I received a call from the retentions department offering me an upgrade on my contract. I agreed to the deal but a few minutes later, the consultant calls me back to say that the deal is just over R100 more. This is a marketing strategy and I found this totally unacceptable. I logged a complaint on the MTN siye and received a confirmation email to say that they will get back to me within 24 hours, 2 weeks later and still no response so I sent a follow up email but they just disregarded it. Having my number on contract for the past 20years and this is the first time I had such bad service from MTN. Makes me want to move over to Vodacom cos clearly customer service is non existent at MTN.