Black Friday stock advertising but never received any. False advertising

I am so disgusted firstly with the service from Pick n Pay trade route mall. I have been to pick n pay this whole weekend since the black Friday special had started for their 6pavk juice promo and everytime I went they said they haven't received stock but when I call in they say stocks are finished. I have seen myself staff taking the juices and hiding it under the counters which I feel is not fair. I had lefty number twice. Phoned them everyday twice. Morning and afternoon yet I got the same reply. They not even willing to help me. I even got told to go check at another branch as they can't help me So the question is, is head office the ones that's not sending the stock or is the stock been hidden for selected people. I'm very upset and I expect to be helped!! Why put a product on promotion if you can't supply the stock. That is false advertising.