50% off sale dispute

On the 15/16 August 2017 I was called by one of homechoice agent offering me 50% off on furniture purchase because i'm a good customer. They said the sale was for selected customers only and I was one of them. I agreed to buy a set of lounge set amounting to R15497 original price. I assumed 50% off will be half of that. I received a statement from them recently showing my monthly installment. When I compared the normal price installment and the sale installment there was no difference. To make matters worse on the homechoice internet site you only have two terms to pay which is 6 months and 16 months, my term was 16 months. On the statement it showed 36 months to pay. When i called to inquire one of the agents said there is no sale and if I cant pay then they can come get their furniture. Please help, I feel like I was mislead in making a purchase. I don't want to return the products but I want to get what i was promised.