Terrible service

Pnp liquor had advertised the brutal fruit case on special for R224 for the 275ml bottles OR the 300ml cans. I went to the brackenhurst store and they had the above ad. I took the case of the cans and when they scanned it, it showed normal price. So when I enquired about the price then I realized that it was the 500ml cans which was taken. I then asked the guy to get me the 300ml cans and he said that they dont stock the 300ml cans. They only had the 275ml bottles which was on special. This is completely unacceptable as they advertised something and then say they dont stock it just so that I am forced to take the item which is smallest in size.