Ocean Basket does not honour promotions

On the 7th December 2018 my family and I visited the Ocean Basket at the OR Tambo airport. A promotion was run where if you order sharing menu items you will receive vouchers. We ordered 2 sharing platters plus 2 starters and we qualified. We whatsapped the till slip as required on the 7th DEC 2018 and I followed up on the 20th January 2019 on whatsapp and on email ********** and still no response. This is very fishy.