False advertising

A few weeks back I bought a defy fridge which was on special for R5499. With the promotion deal you get x6 free pepsi's and a protector surge plug. The promotion happened to end on the Sunday and I saw the promotion the Saturday( the day before the promotion ends). Whenever I clicked on the promo deal it adds the amount of the pepsi's and the protector surge plugs, it gave me a total of R5838, so although the promo deal says its free it was not. I phoned numerous times customer service the Saturday and they also couldnt understand why its doing it, I ask the consultants if I could talk to the their supervisor, but they informed me they had no one on duty, I am still waiting for them to call me back and this happened on the 18th March. Due to the fact I needed a fridge and because the promotion ended on the 19th March, I clicked on just the option to buy the fridge without the promo deal, because I didnt want to pay extra.I also e-mailed customer service on Saturday, with screenshots of what happens to the promo deal when I click on it, they only rep**** back on the 21st March, after the promtion ended and their excuse was that I didnt click on the promo deal and that is why I can't get the free advertised items. I've send them screenshots of what it does when I click on the free deal and also that their sales consultants know about the glitch on their system, but they just apologises saying that I had to click on the promo deal, after explainIng to them numerous times, why I didnt click on the promo deal, otherwise I would have had to pay extra for the items they advertise as free.I feel what they are doing is wrong and that it is false advertising and unfair to the customers.