Charged more for less goods

I wish to make a complaint against Pick n Pay Brigh****er Commons. ( I apologise that this report is late as I was going to just leave making a complaint but upon reflecting, we as consumers receive enough issues in general and tend to just accept them.) I bought a Pick n Pay savoury rolls at R23.99 (the same price as I usually pay) However this time instead of 6 (the usual amount) this time it was 5. When I confronted one of the store managers about this I was told that there was no mistake that dough was the same amount (this despite there were 5 instead of 6 and it was the same price) I feel that the manager misinformed me and feel that we get ripped of as it is in South Africa. Various brands such as Cadbury's chocolate slabs, All Gold tomato sauce and many others seem to think we as customers do not notice that they are decreasing the amount given but we as customers are expected to pay more...