MTN Blackfriday data promo 27 November 2017

I signed up for a 24 month contract on the above date where was promised 100G per month. ( 60 G day and 40 G) at night. Since the time the plan became operational I am only getting 20 G day per month I have since contacted Bridget Bhengu mtn public relations, Mthokozisi Ndlovu executive complaint relations After numerous emails and phone calls I was given a reply from Billie Jean Peters that ‘ 20 gigs was loaded in December I have contacted MTN at Dayan road Boksburg ( where I went 3 Times to sign and finalize the contract. They say it’s not their problem although they all admit ( S Vaughn, marais Tyrone and morey) that my contract for 100 g (60/40) is valid. I am at my wits end. I have sent copies of contract and copies of emails to all concerned but they just slam the phone down on me or are unavailable Yunus