Who called from 5408853271

so far two calls..One on Sunday night..One on Monday Night.  No message left.  Not sure what this is for.

Received 3 calls (2 on 1 cell and 1 on another cell) Tuesday, November 6, 2007.

Received a call from them on Nov. 19.  I did not pick up, but I called back and it rang several times with no answer.

I received a call Dec 10th and didn't pick up. They called back on the 11th and I didn't pick up. I called the number several times and got a busy signal.

got a call  8/20/2008 they got my answering machine and left no meassage
used star 69 and got this number but got immediate busy signal
why isnt the phone company doing something about this?