30gb loaded instead of 50gb

I am so dissapointed at MTN.i took a contract on 11 August for 2 sim cards.They advertised 50gb for 199 so i got 2 sim cards. I had told the salesman i need a lot of data cause i run a small business. Within a week of getting prorata i had no data. When i went to the store i was told they not sure how much data my prorata was which is insane. I even had to hold the phone for an hour with customer service to find that out. At the end no one helped.not even the coverage department knows how much data i should get. What i was told was that the plan i chose was actually 30gb, not 50gb. I was livid and visited the store only to be told its a false alarm. Fast forward to September 1st MTN loaded 30gb and when i went in store i was told they would log a ticket its system error. No one has said anything yet and im frustrated cause for than 20years iv used this network. I didnt expect to struggle from such a reputable network.Shouldnt i get whats on the pamphlet? Why are we being short changed and now i have to run around trying to figure this out. Totally unprofessional.