False advertising

I was embarrassed on my birthday day by Cape town fish market.upon retrieving and registering a loyalty card the benefits were explained and printed on the back of the of the terms an conditions.I went to VNA Cape town fish market for my birthday on the 29/11/22 and was informed after I received my bill there's no birthday voucher as well as 20% off you bill from 4-6pm.. although I provided proof via the website but my waiter did not respond so I paid my bill and left.This is false advertising.