Contract upgrade

I received a call from mtn consultant Prishen on 14 Jan 2021 @13:06 offering me an upgrade on my contract. The offer was: 240 minutes, 1 G data samsung S20 ultra for R749. On 19 jan 2021 @ 09:36 i received a call from Charles Muthulingam from mnt confirming the order. He told me that I can get this for R679 but it will be the Samsung s20+ ... he called me back at 09:56 and informed me that I will get the Samsung s20 ultra for the same price. This morning at 09:21 Charles called me to inform me the courier collected the package from them and will be delivering within a few days.... he now told me that the package includes 100minutes and 500G for R679. I did not agree to the 100min and when I tried to correct this with him. He had an attitude. He made changes to the package without me agreeing to it and spoke over me when I tried to explain what I want and what j was offered. I have been with mtn from the beginning and the service I received now is totally unacceptable.