Police Respond to 9-1-1 Calls -- Not Our Landline

I do not have FIOS.  I have not even had a land line in over a year, since a storm ripped the line down.  I cancelled the land line at the time, but  have had the police at  my house three times in the last 6 months reporting a 9-1-1 call from this address, and quoting a number which was NOT our land line.  They say they called the number back and got a busy signal.  They say it is OUR problem.  How can it be when we not even have a phone line?