Advertising items they don't have/Poor service

Builders Constantiaberg advertised an item on their shelf on special. Although they had no stock of the item they continued advertising it on their shelf for two days if not longer. The staff member who helped me was disrespectful and walked away from me when I asked why this item is still being advertised if you do not have it available. It must also be noted that he refused to go check if they had stock in the store. I escalated the matter but unfortunately both the department manager and store manager (or that's what they introduced themselves as) refused to resolve this matter correctly and were not interested in resolving it either. Their response was that the item is discontinued although they sell a twin pack of the same item. They refused to give me the twin pack for the price of 2 units that were on special. Very disappointed from this experience. I logged a formal complain with Builders customer care line, was promised a call in an hour, which is now 3 days past.