Not keeping to their side of the contract

Took out a new(promotion) data contract(20gb +20gb)with MTN on the 1st Aug 2020 at their New Market Mall branch and was assisted by a very helpful lady Dineo but and a day later pro-rata data was loaded of which I did not make much of. On th 22nd as usual I will recieve all service on my numbers and expected to recieve 20gb anytime on the new contract but to my suprise I only recieved 10gb.

I contacted MTN call center but they could not assist and mentioned that I must go back to the branch. I went back to the branch and again was very helpful and logged a query on my behalf and a week later she called me with good news that my data package was rectified and when asked her about the 10gb still owed to me she mentioned that it should be loaded with the September services on the 22nd.

Well the 22th came and the 10gb owed to me still not loaded, I contacted call Center again and spoke to Smangele who said that she locked a ticket and will send me a sms with a referrence number but to this day nothing. Still not assisted and no sms recieved with the reference number.

MTN loaded a wrong contract but not willing to rectify their mistake yet I must pay a full subscription.