Pepsi Max stock at suppliers taste aweful and taste like expired stock they selling

I buy alot of Pepsi Max and everytime I buy in bulk from Makro the 2l Pepsi's is faulty! The taste is terrible and even Makro's own people can taste the product is not like it should taste! So my question do Pepsi Sa and Marko have some sort of deal with specials that they sell old stock to clients that taste awful? Even this Dec I bought R2000 worth of Pepsi and all of them taste aweful