Chased Away before restaurant closed

On Thursday, 3rd March my husband and i wanted to get sushi from Northgate Ocean's Basket. We got in at 20:40. On entering, a waiter made a \time out\" sign with his hands and another waitress came up to us before we could ask for help and told us that they were closed. Firstly, Ocean Basket closes at 21:00 which means we'd need to be out by then. It was disappointing and embarrassing to be shooed out like that especially when there was still 20minutes. I work in a customer service/sales job and we close at 9pm but we only start cleaning up and closing at 9pm - the time communicated to the public. The people there had 2 tables still occupied by customers. Had they took the time to find out if we're sitting in or take out they would have prepared our meal and we would have left before any of the seated customers. Very saddening and disappointing service "