I want to SECOND the request that you provide the name of the merchant who had the temerity/cheek/balls/chutzpah/cojones to tell you to your fact that you do not know HOW to listen to music. Forums, such as PinkFishMedia, are the ideal place to share this information.
As a recent emigrant to the UK, I encountered a number of experiences, similar ones, and even wrote about in a published letter to HiFi Choice magazine. I never thought they would publish it, but to their credit, they did.
In all my 30 years of shopping for hifi in the United States, mostly New York City and Boston, I have never encountered some of the attitude and gross assumptions made by shops in London:
1, being told that my American cables/interconnnects: Transparent, Kimber and Cardas were sub-standard and were impairing my hearing to the extent that I could not properly evaluate British gear.
2, being told that as an American that I, like all Americans were "MAC-DAC" happy and that if I was ever going to "properly" enjoy digital music I would to purchase a "proper" music streaming system - insert LINN and/or NAME here.
3, being told by one audio impresario, that just by listening to a pair of speakers, he could determine the cabinet composition (material), the cabinet design, and its country of origin.
What do I know? Your mileage may differ. At the end of the day YOUR EARS, YOUR WALLET and YOUR TIME.