It's a nice voice to start off in voice acting. It seems a little forced at times but seems pretty unique, those people generally request more "generic" voices like the deep announcer and the average male/female. You have talent for sure but it might be a bit harder for you to break into the voice acting community, consider going out into the audio forum and looking at the Voice Actor Wanted threads and others similar.

As for this actual writing, it's great at putting in drama early and the dialogue seems mostly realistic, though I would recommend a tiny bit more uhs and ums when it slows down at some times and some more swears when the character starts getting angry. It feels like the background that the pimp explains might have sounded less forced if it's acting as a way to explain how dead Mark is. If you could get it so that the pimp goes "YOU'RE FUCKING DEAD!" before calming down and then requesting money it would not only help you use more variation in your character's voice but also add more tension and make the dialogue progression seem more realistic.