Pathetic Customer Service

What an horrific experience I just had at Clicks Penford in Uitenhage. The shelves show 3 for 2 and I take the items marked with purple stickers. At the cashier I don't get the cheapest one free. The acting manager Mr. Guy tells me that the specials have not been advertised yet and I should KNOW that the specials run in November/December. I asked then why are the shelves marked if the promotion isn't running yet. He ignores me. I speak to a Ms Bailey at the counter and she ignores me too. What on earth?