I'm losing count of the number of times this topic has come up on this forum, and every time we see a host of comments from people who are incredulous that they turned up to spend oodles of pounds on this or that and didn't get past first base. A few observations...
The open-door policy operated by most UK car dealerships means that alongside the potential buyers, they can find themselves dealing with those who are looking for a joyride, are cadging brochures that they can offload to the unwary on eBay or just want to browse. How you are dealt with will have a lot to do with how you present yourself. I'm not talking about sartorial elegance or subtle displays of wealth, but about bearing and behviour.
My MB dealership, which I've praised several times on here, has a reception desk directly opposite the doors. If I turn up unannounced and approach the receptionist to explain that I am interested in buying a car, or obtaining a part, or booking a service, they will ensure that the appropriate person is alerted and, if that person is not immediately available, there's coffee and newspapers on hand if I choose to wait.
More often than not I will know in advance that I am going to visit the dealership, so I will ring ahead and make an appointment; that means they know who I am, why I am visiting and what I am interested in. It also gives the salesman a chance to do his homework. MB has a complex product range and it would be unreasonable to expect every person they employ to have an encyclopaedic knowledge about every aspect and option available for every model (though some undoubtedly will), but if they know someone is coming in to discuss the purchase of, say, an E Class, they can at least ensure they have all the relevant information to hand.
We don't just turn up and expect our cars to be serviced on the spot, so why should we assume that there will be a salesperson available as soon as we arrive. If they are dealing with another customer, are you suggesting they should abandon them as soon as a new one walks through the door? If they are at their desk, how do you know they are "doing nothing"? They could just as easily be preparing to deal with another customer who had the courtesy to make an appointment, or diligently performing follow-up actions for a customer who has just left.
On the other hand, if I walk in and just start looking around the cars, I will usually be left to my own devices, which is exactly what I would want. Occasionally someone will ask me if I need any help, but if I say I'm just looking, then I'm left to my own devices. I know some sales training techniques state that as soon as a "prospect" enters your domain, they have, even if only subconsciously, expressed an interest in your product and you must therefore ensure the visit results in a "conversion" (ie: a sale). I have no time for such techniques - if I want to buy something, I will initiate the negotions when I am ready to do so.
I'm a little bemused by the OP's post, to be honest. He has an established relationship with the dealership in question through his business, yet he has been treated so badly that he feels his only options are to purchase the car outside the UK or to buy a different make of car altogether. Seems irrational to say the least, and the type of language used in the post may give an insight into how the OP's own approach may have influenced the outcome. Companies will sometimes deliberately decline business with a known customer, overtly or otherwise, if they have reason to believe that it is not in their interests to conclude a deal.
As for the chap who posted that anyone who is approaching retirement and still doing a job that a 20-year-old could do is a "moron", all I can say is that you must have very limited experience of the employment market. The fact is that everyone has different abilities and aptitudes; if someone's strength is in sales/customer service, they may choose to remain in that field, and there is every reason to expect that a lifetime's experience of dealing with people will make them far better at it than their 20-year-old counterpart would be. Not everyone is cut out to be CEO material, but it doesn't mean they should be written off.
Bottom line is that it really shouldn't matter whether you're planning to spend £1m+ on a fleet purchase or £5000 on a used A Class. The salesman's approach towards you should be just the same, but so should yours to them. Mutual respect can go a long way.