Who called from 9515527700

Tells me to call this number n when I do it is a working number

A working number or non-working number?

I also rrecieved a threatening call from the IRs claiming to be them and that they will be arresting me for charges and when you call the number back it does not work

Bad recording says hether gray with irs but # is disconnected when u call it back

I received a phone call today stating that I owe almost $6,000.00 to IRS because I did not report the full amount to IRS.  She said her name was Heather Gray & was to call her back.  I called back & spoke to Officer Nicky Smith, she said the police would come to my house & I should hire an attorney.  I got worried about it at first, but my tax person said if there is ever a problem  with your taxes, the IRS will mail you a letter, not call you.