Customer service, advertising and sales issue

We visted a clicks pharmacy (clicks pharmacy bedworth centre). There was a 3 for 2 advertising sticker below the sorbet foaming handwash and right next to it a listing price of R39.99. We proceeded to select 3 sorbet foaming handwash bottels and all of a sudden at the register it was rung as 67.99. When asked we were told that only the one variant of the handwash is R39.99 and the rest was R67.99. My problem however is that these prices were completely covered up with the 3 for 2 advertising special. The same handwash was on another shelve and those didn't even have prices on them. I find this extremely misleading and in my opinion classifies as false and misleading advertising! The staff was extremely rude and was absolutely no help at all! They tried to jusitfy thiss by saying that they have to put the advertising special somewhere where clients can see it. To me this is an unacceptable excuse! This way of advertising in store takes clients for a fool as many do not check the ring up price! I am very unhappy with the overall experience and needless to say, I will think twice before entering a clicks again!