Dishonesty from the manager and cashier at Edgars Cresta

I went to Edgars on Wed 14 August, to the mens section and there was a j-Exchange jeans that was by the sale section and it had the sale price on it as well the red label, when we got to the till, they told us this jeans is not on sale and they dont know why it has a red tag and why it was by the sale section, and I told them thats not fair because that is the price that is on there, and I told them that I am not happy, they gave it to us anyway at the price we seen, but I went back yesterday to buy a shoe, and the lady informed me that they have the buy one get one sale, where u buy anything that is on sale with a red tag and u can get something else fee that is the same price and that has the red tag, but then I realized the jeans that we bought on Wed was also on sale, and they failed to tell us that we could get another jeans as the buy one get one free poster was on top of the rack where we found this jeans, they were dishonest, and we didn't get the benefit of your buy one get one sale, I am very unhappy with this, and would not recommend you to anyone