Data incorrectly allocated for black friday deal

I signed up for the Black friday deal with double your data for the mtn home 100gb. I was supposed to get 100gb day data, 100gb night express data and 40gb youtube data per month for 24 months at R269 per month. I took the deal late November /early december 2021. I received the correct data in December 2021 but in January 2022 on my billing cycle date, i only received 80gb day data and 20gb youtube data. The night data was correct. I aporoached mtn on 135 about this logged a complaint. Got all the reference numbers. Fiest time they logged it incorrectly because when i phoned to get feedback, the agent said that the first agent routed it incorrectly. I already waited 3 days and to be told this. Then the second agent logged it. Then in a day i get a message case closed but no resolution. When i called in, i was told that i needed a copy of my contract. When i signed up for the black friday deal online, it was at www.mtn.co.za. But mtn insists i must speak to mondo. Apparently mondo handles their online business. So unprofessional. Im dealing with mtn so why must i contact their service providers. They should do that. I provided them photos and screenshots of the black friday double the data deal and still a lady from monday says my contract gives me only 70gb night, 100gb day and 20gb youtube. Yet i sent them the photos of the offer snd screenshot. Very very very disappointing. Im a long time customer and u rob me and treat me like this. Three times ive logged this complaint and im being pushed from pillar to post. I cannot take it anymore. Im going to the regulator and my lawyers.