over charged and no discount given

Portesa promised a discount and they never gave us a discount. we spend over R6.7 Million and they promised that on our 3 order we will get a 5% Discount then they said because of the free delivery there was no longer going to be more discounts.THEY SAID the 43 Nelson Mandela Driver Mthatha address was too far to give discounts and the delivery was only done after 3 days while they said its same day delivery.