unfair advertising

apparently spur offfers one burger free on a monday , however i took out my siblings and bought spur burger and i didnt get any asked the guy that was serving us he told me he cant assist with that as i wasnt specific which took me by suprise because normally at maponya mall the give it without you specifying .. to make it all worse i waiting more than 40 min for my order up until the other lady assisted me , and kuhle came 10 min later by the time he got there i was enjoying my meal and he didnt even show any remorse . the service i got was phathetic im never going to that spur as the people there show no sense of urgency