Won't honor contract

I upgraded 2 of my numbers at Dainfern Square on black Friday. The store did not have stock but they promised the handsets would be delivered by Friday 6th as I am going on holiday. I started calling the store from Wednesday and the were dis interested saying they had no control over phone delivery. By Friday only 1 handset arrived so in instruction from MTN direct (Gift) I told the store to cancel with the intention of then ordering from MTN direct for delivery to holiday destination. Now MTN will not hour black Friday deal as they say it has expired. I have proof of my original order as well as phone logs of all my calls. MTN you need to honor your contract and deal with the bad service at Dainfern.