My father had a similar experience with a Merc dealership and it too cost them the business (quite possibly the company account as well). He was looking to order a CLK convertible at the time for his company car, he stood in the dealership waiting for a sales chap (anyone would have done) and was essentially ignored for about half an hour. He spoke to the receptionist to pass a message onto the manager stating what he was here to purchase, how long he had been ignored and that he was taking his business to the next towns dealership as they would probably welcome the sale.
Needless to say that the other dealership were superb and that was where his car was ordered from.
Perhaps its a Merc thing... I have not had dealings with them (not rich enough!) but the BMW repair/spray shop that I use for any paintwork I have done are superb, cant do enough for you (Guildford) even though my cars are Subaru.