<human>: I just got a call from Comcast demanding I fax them a copy of the deed to my house to continue service with them.

The back-story: I've been living in Chicago for the past several years, and had been a customer of Comcast during that time.  I paid every bill in full and on time.

About a year and a half ago, I bought a house in Baltimore, but was still spending much of my time in Chicago, so I continued to use Comcast in my Chicago apartment.  Then a few months back, I got rid of my Chicago apartment and decided to live in Baltimore full time.

So last week I finally got around to transferring service from my Chicago address to my Baltimore address.  It seemed to be easy enough.  

However, today I got a call from Comcast telling me that because a previous resident at my Baltimore address still owes Comcast money, they need a copy of the **deed to my house** to prove that I am the current resident.  That's right, the deed to my house, they said nothing else would suffice.

Can you condense the text into three sentences or less?
<bot>: So because a completely unrelated customer (different name and everything) racked up debt to Comcast years ago, a great customer (me) has to send Comcast a copy of the deed to my house.