Back in the old days I used to work in a shop - well a department store, but same thing. Now and then you would get strange people in who liked to think they were somehow getting the upper hand on you by not letting you engage with them at all. They were very common in the "technology" type departments (well what passed for technology in those days!). I think ity was because they felt they had superior knowledge, but couldn't afford it anyway.I work in a 3Store. I am a sales person, therefore... it is my job to sell things. Some man walks in. He has been in before and has had a look around and then proceeded to tell me that I will never be able to match the plan he's with on o2 and walked out. Fair enough.
So he comes in again, I say hello! and smile. I get a dirty look. I ask him what's brought him in today, he says "just looking". This is not an answer to my question. He said this while looking at the iPhones, so I try to get a conversation started with him and ask if he's been in the store before as he looks familiar, and he says "probably", with his back turned to me.
Now, you get a lot of arse holes come in who are "just looking" and are literally wasting mine and their own time as they blankly stare at dozens of plastic demo phones they have no idea about or cant afford. People don't realise I'm not some comission hungry freak and I do have the relevant knowledge and expertise to help them make an appropriate handset and plan choice. There's no need to be so bloody ignorant. Manners don't cost a penny. Stupid prick. Karma's gonna get ya.
Don't take it to heart. Just smile, be polite, and go find a genuine customer (which you probably already do anyway).
Good luck. There are some miserable people out there!