Pick n pay terrible service

Pick n pay Woodmead had special for dog food any five for R95 when I am done paying I realise that I did not get that price so they tell me to go stand in another queue after I told in a queue already then I ask for the manger they call some lady who tells me there's nothing she can do I need to stand in the another long queue after standing in one. I then ask for the store manager who never comes