This is a scam.  Here is info from IRS website about reporting this to IRS - please do.

'If you receive a phone call from someone claiming to be from the IRS but it is a scam

'RECORD the employee's name, badge number, call back number and caller ID if available.

'REPORT THE INCIDENT at [email protected] (SUBJECT: 'IRS PHONE SCAM’)'

For those who might have talked with the caller & given info -

'Please REPORT IT TO THE TREASURY INSPECTOR GENERAL ADMINISTRATION (TIGTA) and FILE A COMPLAINT WITH THE FEDERAL TRADE COMMISSION (FTC) THROUGH THEIR COMPLAINT ASSISTANT to make the information available to investigators.'

https://www.irs.gov/uac/Report-Phishing