Touching on something brought up earlier about not being able to do the character's voice in other projects - not the case. People do their character's voices all the time in other projects, even ones that are for profit. Look at Robot Chicken, they lampoon everyone and constantly get the actual voice actors to voice the characters they're making fun of. But in the case of doing a voice for a student's fan film, nobody cares. If he started generating money on it and claiming rights to the IPs, that would be a problem.
As for payments and contracts: If you do voice acting as a freelance project, you can charge whatever you like. Some people do it for free. If you work on a SAG project, you get $450 an hour, minimum. Dred is, or at one point was, SAG, but for personal projects you don't always need to get SAG involved.
So all this "there was no contract" talk is bullshit. If I agree over an email exchange to do work for you, and you agree in that email exchange to pay me for it, that's a legally binding agreement right there. It doesn't matter a hill of beans if the emails took place on Facebook or Gmail or any of that shit. Yes at some point if it's a big project you should get it in writing, but not all jobs are like that. I do plenty of freelance work that I never sign contracts for.
So never before, in your life, have you ordered something off the internet? EVER? You've never downloaded a game on your console of choice or PC?