Ouch! Not the most ideal situation. I would just keeping ending the call, don’t even answer and she will soon get bored she’s just mad.
If it’s your AW she has found and your concerned, I would maybe go onto seeking services on the days I wasn’t available so the search comes back invalid then change your name to something very similar, there’s only so many times she will search with nothing coming up. I’m only on AW so I don’t know about any other sites but someone else on here will.
You could explain to her that this is your job, you don’t fancy him and have no interest in him. HE was the one who came looking for you! Threatening to call the police could work too, no one wants to be arrested for harassing escorts their boyfriend has been seeing.