Worst service ever

On the 30th of November during your black Friday buy 2 get 1 free promotion, I went to Woolworths Sammy marks and made my purchase there, I was very specific on how I was giving the cashier the items, I was giving her the 3 items at a go, what she did is she failed to tell me that I was going to make one payment, and this would result in me getting the lowest item on the slip free.

whereas i was giving her the items of the same amount thinking that that's how their system would discount. I have since logged a complaint in store, on email and on twitter and no one from Woolworths or the store has contacted me since.