False advertising

I bought parmalat sliced mozzarella cheese 24 pack On the packaging it clearly states 24 which is (2 sections of 12) individually wrapped slices of cheese guess what to my surprise i bought it last night opened it and used 5 slices this morning i used another 5 slices which in total is 10 unless I was left behind when they change 5+5=10 to 5+5=12 so i decided to count the remaining slices and well please tell me why is there only 10 slices left if my calculations are correct that is 20 where is the other 4 which you actually get charged for and which is calculated in the weight of the product which is 24x16.7g= 400g so we pay for something we don't have false packaging and falls advertising at it's best