Don't honour Black Friday 2017 Price for contract

On 25 November 2017 I went to MTN shop to get the Mega Deal of 100GB data for R499 and was told by MTN employee that MTN system is having problems and that they will phone me when I can go get the Sim card. I asked her will I still get my full 100GB and she rep**** yes.

Got the sim a few days later and again I asked her will I still get the 100GB for R499 as advertised and she said yes but will be prorated till December 2017 which I said is fine. Got about 15GB then. At 21 December 2018 I only got 80GB and was missing 20GB. Made a call to customer care and got my 20GB but the bill showed I owe MTN over R900 for 1 month.

I paid then the R499 since was told by MTN store there are problems with billing. In January 2018 again only got 80GB and again missing 20GB and now the bill shows I owe them R750 and again not the R499 as per Mega deal. Emailed a few times but MTN ignores it.

I see alot of people have this problem and MTN don't care about the customers since they get their money. I think it would be better to just go back to the store I got the sim card and see if I can cancel this contract since MTN has no interests in helping anyone.