Why bother putting things on special when you going to be charged more?

So disappointed in the service that I received this morning from Woolworths. I was literally the first customer as I arrived before the doors opened at the Palmyra Junction Woolworths in Claremont. Purchased 2 bags of citrus fruits which were marked at R24,99 each but if you buy 2 packets you receive R10 off. Got to the till about 8.08am as I left the store I check my slip and realised that I had been charged R32,99 for one pack and R24,99 for the other and that the discount had not kicked in. The cashier who had helped me was not on duty so I went to another cashier. The cashier referred to me as "she" when she called the supervisor who eventually called Management. Turns out the promo wasn'r registered on the system so Management told them to call whoever. The thing is this debacle took a good 10 minutes not once during this time was I offered an apology AND how many other customers had/will be charged R58 for something that should be R40? Not on woolworths I am not even going to bother phoning customer services as you've wasted enough of my time ...