Who called from 2162820239

Got 2 calls from this number today and they hung up as soon as I answered

This number keeps calling the office, but when I answer, I here a tone like someone pressing the button to dial, and then they hang up.  They call about 10 times a day.  Is there anyway to stop it.

I receive numerous calls at the office on a daily basis. I've decided to let it go into voicemail b/c no one says anything when I answer.

This may be a trade magazine renewal service but they also are involved with providing info to collections agencies. They use the trade magazine qualifications angle to get info on where people work.

Someone keeps calling me at work and not responding when I answer.