Upgrade Query

Hi. I called vodacom on the 26 November 2021 for an upgrade on my contract. I spoke to a certain consultant who promised me a deal of unlimited calls, unlimited sms and 15gb at R699 less 25%. I have agreed to the terms and conditions telephonically. I received an sms at R699 and the consultant assured me that, that is not the price I am going to be paying. A week later the consultant called me and informed me that the system rejected the deal. How is that possible. I called on numerous occasions and have not gotten feedback to date. My last call to vodacom was on the 28 December requesting that my deal be honored however on the 29 December I received an sms stating that my contract deal has been reversed. How and how gave vodacom that authority to reverse a deal that was already approved. I was just quearing my contract pricing. I would like this issue to be resolved today and my contract price promised to me on 26 November 2021 at 11.45 am be reinstated.