False advertising

I went to Pick 'N Pay Express Fourways today, I saw they had some good deals so I decided to purchase. I was interested in their chocolate special, the ad said buy any 2 cadbury lunch bar, PS, 5 Star or Crunchie for R17.90. I took a lunch bar and PS but to my surprise the teller tells me that the deal is not on these items. I ask her which one's are and she couldn't say. I told her to call someone to override the price as I want what I saw on the pamphlet, she mumbles to her colleague and then tell me they working night shift so there is no supervisor. What kind of store operates without management? On which items is this special applicable to? I'm very disappointed in the service as these ladies were not willing to help. It is a sad excuse of a shop