I Let the phone ring a few times then piked it up.  No one on the line, some sort of robo call. I've been getting calls from debt collectors about my neghabor's son.

Got a call from this number, but didn't answer since I don't recognize the #. Called back a day later since they didn't leave a message but got a busy signal.

sounds like a bill collector to me. Watch out.  IF you call back, use *67 to conceal your number.  Someone wants to get some money from you--probably a call center.  Prepare to change your cell number, or get a pre-paid from Walmart, etc. -- or you are in for it!

Answered the call today from this number and it really was AAA (American Automobile Association).  I had renewed my subscription 2 days late and they did not have a record so it really was AAA Retention.  They couldn't have been nicer!!!