866-940-5788

I've received messages on my answering machine from "Citi Mortgage" 2-3 times a day for the past two weeks from this phone number.  I do not have a mortgage with them.  Called the number and the following was the message:
  Thank you for calling Citi Mortgage.
  For access using your Account Number, press or say 1.
  Access using your Social Secuity number, 2.
  Third party service providers, 3.
  Para espanol, a primo quattro.

After the third time of the recording, I was asked to stay on the line for the next operator.  I was finally transferred to an operator who asked for my account number.  I finally was told this was collections from Citi Mortgage.  I asked them to remove my phone number, which they claimed they cound not do.  Very unprofessional sounding, seemingly unprepared for every question I had.

Is this a fraud?