I went to a Teen Mania event and they started calling me from a group called "Global Expeditions" to go on a mission trip. They will call once then not call for a month... I havent heard from them in over 3 months... I have told them not to call anymore. What they do is have the college kids on there campus do the telemarketing calls to "do there part" and get the word out... it also counts as credits for them!
When you go to these events they will get you to fill out a card to win a prize or to have info to contact you for mission trips so what ever # you put they will call you on!