Poor client service

Good day

I am writing this in connection with my brother and sister in law, they had made a booking for Valentine's day, but when they arrived there, their table was given to someone else, so they had to leave and buy dinner by our roadhouse, how is this possible, a booking was made so why couldn't you guys accommodate my brother and sister in law??? Very unprofessional from you guys, also, why give their table to someone else in the first place???? A booking was made, very bad client service.