Where I live, SBC offers two basic levels of service: 768/128 and 1.5/512 ADSL connections. Before a customer signs up, they are specifically told that speeds may vary depending on the distance from the CO. Obviously, the further away, the smaller the maximum bandwidth. However, just because you're closer, doesn't necessarily mean you're going to get better speeds. First of all, they'll cap you. Secondly, they don't offer service outside the tested ranges.
I don't currently subscribe to SBC, but when I did a while back, I was almost 16,000ft away from the nearest CO (18,000 being the maximum). Any distance within this range should receive 768/128 no problem, assuming other factors like your house's wiring or interference from other devices aren't at play. The business class service (1.5/512) was only available to locations less than 12,000ft away.
If you're not getting the speeds you signed up for, most DSL providers have a provision in their contracts to allow you to cancel early without penalty. However, I think it would be incorrect to say that the company "has to" resolve it for you. They can try, but in the end, it could just mean a cancellation in your contract.
~cdogg
[tab]"The secret to creativity is knowing how to hide your sources"
[tab][tab]- A. Einstein