If they dont want to see you because of your race then move on. Everyone has preferences. Of course it's bad to judge an entire ethnic group based on actions of some turds, but that's how it is. If a girl sees say 30 clients in a week, 5 of them being asian and 3 of those asians try to haggle prices and/or try to get free time, then she may decide that it's not worth the hassle and chose not to see asians. Obviously being in England where the majority of people are caucasian, it would be business suicide to chose not to see caucasian people, even if a girl experiences 'issues' with mostly caucasian people, she will still chose to see them.
The term asian is a blanket term, it covers a number of different countries, and within that you have tons of different sub-ethnicities, and then of course in UK you have those born here and have assimilated into the british culture, those who chosen not to, and those actually born and moved from south asia. It can be hard sometimes for even asian people to differentiate just by looking, so a non-asian would not have a chance to tell difference between a british indian and an indian born in india, just by looking.
It's a culture thing, over in asia, they haggle for everything. Over here it's not accepted but they can't (or chose not to) understand that.
If I see a working girl, and she chooses to judge me based on colour of my skin before even meeting me and thus proceeds to give me a shit service, even though I am polite, hygienic, and opposite of what she may have experienced with other asians, then that's her problem.
I have met a few working girls who did not know what to expect but were pleasantly surprised by how nice I was.