Who called from 4159264147

Received the call from 4159264147.The lady said that she is Julia Smith from IRS.And I am supposed to call back.
Checked on this site and found that this is a scam.

Julie Smith calling and leaving message to call back regarding IRS problem.  Never anyone on the line when you call back.

Same this left message stating IT'S imperative to call back before further action taken

Called my cell phone two times on January 29th. Left message on voicemail. Said not ignore this call or action will be taken against me and have a nice day. Left number and name Julie Smith with the IRS.

I've received two calls from 415-926-4147 asking me to call back saying it's the IRS.  The first time I called back I got a person who insisted that he was a representative of the IRS but when I asked him where he was located he hung up.  How can I stop these calls?