False Marketing by MTN- 24 Months advertised but 36 months contract.....

A deal was offered on MTN business, Samsung Galaxy Note20 Ultra 5G with 6.5gb at R1149 pm x 24 months. However when I try purchasing it online as well as in store I am told its not a 24 month contract but in fact 36 months. I have proof as I downloaded the offer and showed it to the sales agent that it notes 24 months. They failed to honor the deal. My last mtn contract expired last month. I have a healthy business without any debt and I have a clean credit record with sufficient disposable income, however they have turned their backs on the deal. All the necessary documents were provided. I was told by someone, that in order for them please me as a client, they will act as though they will honor there mistaken promo, then will deliberately advise that I failed the necessary credit checks. This apparently happened to many during there black Friday Deals. I am prepared offer a deposit should this be the case just so that they can honor the advertised deal.