1st day of special and no stock

SPAR crescent have an anniversary special starting on the June 18 to June 21. I went in at 1pm on June 18th to buy the mooi river butter advertised for 2 for R50.the floor manager said they sold out and waiting for stock to arrive. The guy in charge of the fridge says sold out and no more stock coming. As the shelf was empty but sign stating only 2 per customer. Don't know why do shops advertise and don't stipulate the limits on the advert. I wanted to buy a case of butter but didn't get 1.I just wasted my time and petrol going there.