Poor service at trueworths

Me and my mother went to Trueworths at Thabong mall in Sebokeng and they had items marked down. She asked the teller about one DH skirt and she said to her only the marked items are on sale. So she took a 2 pack set of t-shirts marked R340, as we went to the till point the teller by the name of Lerato scanned and said the item was not R340 but was R520. So I said to her but the marked price is clearly R340 and we should get them at that price according to the consumer act but she and he manager refused to give us at that price giving us the excuse that the sale only starts on Sunday. Sale items if the sale hasn't started is dermacated with a tape clearly showing consumers that they are not supposed to take from the marked items. I'm very dissapointed at Lerato and her manager for handling the situation in such a poor and unprofessional manner. They know better and i urge the area manager to do something about this situation as I'm hugely unsetisfied.