Spur 50th birhday special from 24 to 26 October

I received a sms with a add special.Order a steak or chicken schnitzel plus a sauce for R50. We went to spur with my family off 5 for the special.When we placed our order I asked for the steak with sauce as per the sms they send me.I was told by the waiter and manager it is a miss print from head office.Why advertise something if you cant keep to it.We left and went some where else.