Worst customer service ever

So we went to Dalview Spar Yesterday afternoon with my Brother in law my wife and my daughter.... We walk through the spar getting what we needed for the week and the got to the sweets. There is a special on cadbury slabs for 19.99 i think and the pepperment crisp was in the same rack as all the other we took a rolo and the pepperment crisp slab and went to pay we got to the cashier amd she rang all ouer groceries up and we saw the price diffrence we told them that it was all in one rack and i went to go show the cashier (vicroria) she then said to me that I must Learn to read what is on the label but obviously if the big label displaying the special over powers all the labels that is the price you will pay you dont expect and elderly person of 70years old to bend down to the floor to read all the labels. I then said to her its fine and we went back to the tills and walking back she then started to smile and Laugh at me. My wife then went to the manager of the store and explained the situation to him amd he then said to her maybe you should start reading the pamphlet of the stoor... He then got so rude towards her that i eventually stepped in and said to him that I will take the matter further with the right authorities witch he rep**** to "Do what tou want to" This was the worst service we ever got and for people to treat us like that was unfair...