Black Friday MTN **** deal

I am fed up with MTN. Black friday deals my ass. I took out a new contract with MTN on the 28th of Nov. The black friday special was R149 p/m for 13 months and then you get 30gig of data a month. I took a screenshot of the deal. I then received my sim card and a email stating welcome to you 20gig gold internet and was given 20gigs on the firsf of December. I phoned them and queried the amount as I took the black friday special and and was suposed to get 30gigs. After numernous calls and emails, today i get a responce to say I got 15gig anytime data, 5 gigs promo and then a once off 10gigs for joining. And that is the package it took. And the ly closed the ticket. So now after explaining it was a black friday deal they will hold on to the fact that i did receive 30gigs but 10 of it is a once off. No where does that get stated in their advertizing. Everywhere it was 30GIGS for 1w months. *****. MTN is *****. The only reason I am with MTN is because Vidacom, telkom and cellC does not have signal at my workplace. But will never recommend MTN. Useless