Disappointed in Mugg and bean Rustenburg

Really disappointed in Mugg and Bean Rustenburg. This was our favourite breakfast place. Had a bad experience now for the third time. Went there on Friday 27th December and order a chicken mayo sandwich. The lettuce on the sandwich was brown, the chicken tasted sour and we've waited so long for our food. Cant believe they give food of that quality to customers. We've send the sandwich back and even the waitress said it really smelled bad. Don't know what is going on at this restaurant, food is of bad quality and the service is poor. Never complain,but after the 3rd time I am really disappointed.