Misleading adverts

I am disappointed in Makro's advertising regarding the eBucks that you earn when you buy something from their stores. They advertise that if you buy an item to the value of R4000.00 you will earn 4000 eBucks (FNB card) but this is not true. I bought a fridge last month but I did not get my eBucks as per their advert. I contacted FNB to check why my eBucks have not been allocated and they explained that there is a calculator used for allocation of your in-store spending, you don't get the full eBucks as per your spending.

Now why is Makro misleading us? this is somehow false advertising because there is no explanation of "this" on their adverts.