WORSE SERVICE EVER!!!!!

I received the most terrible service yet, I telephonically placed an order with a Salome at Petros Belgravia for a Viva Meal. Whilst placing my order with her, she is speaking to her colleagues instead of assisting me. I had to repeat my order more than once (You think that's bad). Upon my arrival, I gave the cashier my name, she tells Salome and the two are speaking and laughing (I couldn't understand as it was in another language). I asked to be seated at a table instead, Salome says immediately NO and that the meal is boxed as Take Away. That's a poor excuse as we are paying customers and could have ordered more items from the menu, if we were seated. Thereafter, my husband tries finding us a seat, there is a Petros waiter (clothed in uniform) sitting in a seat, SLEEPING. My husband tells her that we would like to be seated there (my parents and nephew present), she tells him that she is on lunch. When my husband asked her for the manager, she rep**** his more than welcome to call and continues to sit there until the manager Patience arrives who then spoke to her. To top this off, another customer takes our seat we just disputed, Patience does absolutely nothing. We had another customer who witnessed this transpiring and offered his seat as we were leaving. Why? Was this not the manager's responsibility to immediately go over and explain the situation to the other customers? she stands there and doesn't attempt to resolve this and where do you find staff of a restaurant sleeping and not attempting to move as it's still "her lunch"? It seems the manager has no control over her staff. I would not recommend this branch to anyone. The staff is not friendly and seems like they would prefer not being employed at all. I'm really shocked at the level of service.