Sorry no mugs after asking twice

This morning I was in their store 7th August in 18 Wellington Road Durbanville for the 3rd day in a row because i'm on training in Durbanville and every morning i've seen the ad of the Brekkie crunch wrap with cuppachino and then you get a free mug. So because I collect mugs this morning I decided to order 2 meals before the time I asked the cashier Poni if they have the stock and she said yes so I ordered. After returning from the toilet she said sorry they out of stock and called the manager where he just rep**** they did not receive yet he will call me I don't stay in this area and i'm not driving back here. How can you advertise something ask of you have stock and then all of a sudden not have. This is false advertising just to get customers to buy something because on the massive board they advertise it when you walk in it should say out of stock and it does not say anything. I am going to take this to the consumers board because you can't make a customer first pay for a product and then afterwards tell them sorry no stock because of that were the case I would not have bought anything there instead I wasted almost R100 for nothing. Very dissapointed!!!!