Who called from 9107820000

I have answered 3 calls from this number in 2 days and no one was on the line.

2nd call today from this number. This time he said he was calling to do a survey. Don't know what for 'cause I said I don't do surveys.

1 minute ago...no one on the other end.

Called about 330 while was on other line - didn't get to fast enough. When I call number back I hear dialing beeps but it never rings. Maybe number is cancelled or calls blocked. Not up to any good surely.

Called and ask for my son. Hung up immediately