Bad service

So this previous friday I went to wimpy in heidelberg in the western cape and the service was horrofic Wimpy is currently advertising a special which goes for R99 rand so I tried to order that and the supervisor said they cant serve specials after 12 which I could not inderstand because nowhere did they stipulate a specific start and end time for the special so the supervisor said she has to call the manager because I was insistant on the special so she went made a call came back told me the manager said no reason being the special had a bottom less cooldrink which does'nt make sense because I wasnt even interested in the cooldrink and only then I found out the lady I thought was the supervisor was actually a cashier and that there was no manager or supervisor working on that shift which explains why the staff was sitting and watching tv where the client or customers are supposed to sit which does not look good all Wimpy is always specific about times and sit downs and such so why drop the ball with this special