who are these people?

Called me once, I told them I'm not interested and asked how they got my cell number and to stop calling, they hung up on me. Five minutes later a different person called from the same number and as I was letting her have an ear full, she hung up on me as well. I've had odd phone calls from 3 different numbers just this week, one number says invalid when you call it back. The other number is IMC and some sweepstakes thing and this number is a sweepstakes things as well.

SCAM ALERT!!!Do not give any info Even if they call you by your name.They claim it is a sweepstake and your credit card or bank entered your name NO BANK OR CREDIT CARD COMPANY DOES THAT.Tell them they have the wrong number and no one by that name lives here.