Incomplete product

I'm very disappointed with MTN's Black Friday special. This special was a R 199 package that includes 30GB of data (10GB night time and 20GB anytime). In addition, it included a free three months' subscription to Showmax. In a nutshell, I was only given a portion of the data. After numerous emails and visits to the store where I signed the contract (Cresta), I have only been given 20G (10GB night time and 10GB daytime). My data was activated in November 2017. I've tried their call centre, been at their store numerous times and sent emails back & forth. (I'm still waiting for the shop assistants to email me a copy of my contract.) On the 2nd of January 2018, my account was debited R 343.20. I understand that I received pro rata data of around 8G before the 14th (which is when my full normal data should have been activated). However, I don't understand how I got debited an additional R 144.2 when my subscriptions only show 20G. It's a little frustrating that I don't get a response from the shop assistant and that nothing is adding up. In addition to all that, I still haven't heard back from them regarding the Showmax subscription. A consultant at the Mall Of Africa store told me that there were numerous applications processed, where they had an issue with Showmax. I later went back to the Cresta store and was told that there is an issue with Showmax and MTN, and that when MTN users on the package try to login or create a profile, they are told they have in sufficient funds. So I was asked to add my name to a list and they would get back to us once that was sorted out, which I did. Upon returning to the store a few days later, the issue still wasn't resolved. Another shop assistant sent me a link to Showmax but as the previous shop assistant had said, it required me to have a certain amount of airtime in order for it to work. So in a nutshell, MTN promised a Showmax subscription that they hadn't checked thoroughly. I really feel that MTN can sort this out with Showmax without making it the customers' problem. They can send customers the amount required to activate Showmax, and then sort it out with Showmax. I am happy to provide the emails I've exchanged with the shop assistants and to provide any other details needed. Regards