False Advertising

I visited the Store yesterday saw a Promo on the Window which said 3 for 2 on priced to go items, of which I bought 3 priced to go waist wallet belts was told I can't have the 3rd one for Free as the Promo is finished. I then asked the lady to go see WATS written on the window and I was told by the Supervisor that I can't have the 3rd wallet as the promo is finished... I mean I don't know that and I bought this after seeing Wat was written False Advertising on another level... I called their Head Office yesterday and was told I'll be contacted after 24hours of which I'm still waiting for the call I mean I wasn't helped either by the Store nor the Head Office..