DirecTV Denied services based on address?? Why even run my credit??? Internet

On 10/29/2012 I applied for services with DirecTV. They checked my credit and told me I was approved and then also received 21.50 from my credit card to start services. I also made an appointment for them to install my services on 11/8/2012. November 8th came around and 2 hours into waiting for a service person to come and install the cable I called DirecTV to insure the person was coming out. I was then told the order had been canceled because there was a problem with the account.

First of all, 10 DAYS HAD PASSED AND NO ONE FROM DIRECTV BOTHERED TO CALL AND TELL ME ABOUT THIS "PROBLEM WITH THE ACCOUNT". NO ONE CALLED ME TO INFORM ME NOT TO WAIT FOR A SERVICE PERSON TO INSTALL BECAUSE THEY WEREN'T SENDING ANYONE OUT. 10 DAYS PASSED AND NO ONE FROM DIRECTV TRIED TO REFUND MY MONEY BACK TO MY ACCOUNT.

When I inquired as to why my order was canceled they asked if I knew someone named "April". I said yes, she was my sister. They proceeded to tell me because she hadn't paid her bill, they were denying me service. Their reasoning was because I lived at the same address as she at some point. My sister and I, along with 8 other people lived at the same address at "some point". I lived at the same address as my sister for 1 year, and since have had my own address, while they all continued to live at the "address" for 2 more years. How can service be denied to someone not because of their credit, but because of their address?? When did this become law? I want proof this is lawful!!!!