Who called from 9737556600

Didn't answer call.   They left a message to call back and identified themselves as a Debt collector.

call came in from this number (I don't answer calls from unrecognized numbers); they left no message.

IRS scammers

again today, call came in from this number (I don't answer calls from unrecognized numbers); they left no message. this happened also 4 days ago so I will now block this #.

Called back and it's Dynamic Recovery some debt collector; said someone else owed them money.