Who called from 7862190455

Repeated phone calls from this number...Answered one time and they hang up! Called back and it is always busy?

They call me every day with recorded message about lower rates on my credit card.  Tired of them calling.

They called me too about 30 minutes ago.

As soon as I answered they hung up.
Makes me feel as though their getting some kind of information from me by establishing this connection.

Just got a call from this number about 20 minutes ago. I did not answer. Upon trying to call them back, all I got was the "busy tone."