Feels cheated after 3 cars bought.

In March 2015 my husband bought his brand new Ranger from Fury Ford Woodmead, so we decided to buy my son's 18th birthday car & my new Eco Sport from there as well. Saturday, 25th July we visited them and decided on two vehicles, the Eco Sport and a Second-hand Figo. The Figo was bought cash and we paid R100 000 dep on the Eco Sport. When we took delivery of the vehicles on Friday the 31st both of them were almost empty! We barely made it back to work! Then I saw the offer next to the highway that states the following: BUY ANY NEW VEHICLE FROM FURY FORD WOODMEAD BETWEEN 25 & 28 JULY '15 AND RECEIVE A FREE GENERATOR OR A WHOPPING R10000 FUEL! It was also on their Facebook page! When we questioned the sales person about this he told us it's because they gave us discount. As far as I know they gave us some discount because we bought 3 vehicles from them in 5 months! Which two of them are BRAND NEW! If that is their excuse why were we never given the option between the offer and their discount? We were never told about this offer? We now have 3 Fords in our family, and this actually leaves a sour taste in my mouth, cheated. Fury's slogan says: doing the right thing! Are you sure?