Yes, I have encountered this problem before, and have felt your pain. There is an old saying: "We don't pay them to have sex, we pay them to go away afterward." A bit brutal, but basically true -- sex is available for free with only a modest effort. Sex without strings attached costs a bit more (even if we're only talking HJ).
Chances are good that you may get a pouty lip from her when you choose someone else. But that's about it. If you want to be kind beyond what is really needed, you can go one more time with her, and during that session, let her know that next time you will try someone else, for variety. You can even ask her for a recommendation if you like. When she pouts and complains, you can say "but I'm not your only customer, am I"?
Unless the girl has eyes on you as a regular BF, that will be the end of it. And if she does have eyes on you as a regular BF, best that she finds out now that you aren't in it for that reason (unless you are, in which case, you're toast).
So, expect some playful disappointment from her, but that's it. If it's all too much to handle, just go to another shop where bros have given great reviews. If you can't solve the problem, avoid it.
I did have one bad experience one time. There are two Vietnamese lounge girls at Familia Nobre sauna in Macau where one absolutely hates the other. But I like them both. The sassiest one of them (Mi), told me that if I kept choosing the other one (Nguyet), she would never talk to me again. I politely told Mi it was not her place to choose my friends for me. True to her word, she has never spoken to me again. It's all part of the punting life
Gherk