The cable companies have been black listing addresses for YEARS!
Certain addresses have a history of bad debt, and the cable companies will literally put a block on the address and either force the new customer who wants service to pay the back balance or jump through hoops to prove they are not associated with the previous account holder.
Comcast does this all day long. Charter/Time Warner does this in extreme cases, but usually they make the new customer pay the first bill and install fees in advance.
I am not aware of Directv/AT&T doing this same practice, I will however say that they do run a background check on all new customers and if they find bad debt before you get installed they will cancel your install without warning.
Based on this situation, there is nothing a retailer can do to fix this.
There are 1 of 2 possible explanations for this original posters situation.
1) Directv is associating bad addresses, which could be a new policy.
2) Something is linking this customer besides the address to the other customer. Perhaps family member, credit card, email address.
There is usually an exception process for the new customer to prove they are not associated with the previous account holder.
I will say from experience when I run into this situation, and the provider is requiring payment of the old debt in full there usually is a legit reason why.
People think Huspsnd, wife, kid, brother, sister is considered a new account but in reality the entire household gets associated with the debt from someone else in the household.
It's at the point where when I do a Comcast order, and we run into an issue with a previous debt, I don't even waste my time doing a research ticket and instead refer the customer to the service center or 800-Comcast.
9 out of 10 tickets we submit to research due to a bad debt for an address, or for a customer because the system saying the customer owes a bill.
We usually find the following
A) Finds more money the customer owes on older accounts.
B) we find the customer let someone else use their name.
C) we find the address became blocked due to another family member running up a bill.
D) identity theft, but the customer won't file a police report because they likely know the person.