This is what Brigitte says about them, Charlotte. I don't know but it does sound like they employ many teachers , second language English teachers. No self respecting natural English speaker would put up with little ten minute lessons and do lesson evaluations which take as long as the lesson. Pop them in the bin quickish like.

Brigitte - 2015-09-24
Re Mentorphone
I worked for them for about 3 days. The training isn't paid, I knew that. It's not a scam but you basically have to have a certain amount of hours, like morning or evening, open but you have all these little 10minute lessons. By the end of your shift you've worked about an hour, since its paid by the lesson only. And, the kicker is, you have to do these ridiculous lesson evaluations. They're long and take longer to do than the lesson itself. And you don't get paid for it.
Don't waste your time.