I found this company advertising online last year called I Speak U Speak or ISUS for short and checked it out. It´s a great company based in Spain that offers telephone classes to business english learners. The great thing is that they let you work from home. All you need is a fast adsl internet connection, a computer and a headset. I´ve been working for them for the past 4 months and everything´s been ok so far. They´re very professional and have a great online system for attendance, lesson and lesson planning (so you don´t forget the lessons you´ve already taught), etc. Lotsa great stuff! Check them out at jobs.ispeakuspeak.com/isus-job-description/
Did I understand it properly or did you just say you are teaching through the telephone? I cannot imagine that it is professional work, teaching someone you do not know, or see through the phone. I consider it strange. And how about the people you are referring to on the phone? do you know them? or see them somehow? And what about the payments? I cannot imagine how you might get paid for teaching on the phone. That definitely does not sound very professional to me, actually, it sounds like being a big rip-off.