Bad customer service

Sunday the 15th of November 2020. I attended Park acoustics in Pretoria, Jack Daniels has a stand there which sells to the public, I purchased a drink and was then asked if I would mind being in a promotional photo, i was given a complimentary bag to hold up and the photo taken. In the bag was 3 vouchers for 3 drinks valid for that day, unfortunately I was told by the jack Daniels staff that the ticket was not valid for that day ??? I still have the 3 tickets. Moral of the story I guess is do not hand out vouchers that you cannot accommodate