I will say this is the first I've heard of BP compensating station owners. I had heard previously they had made no effort whatsoever to help. Glad they decided to stop being a dick about it.
Also I have read the majority of gas station owners are still under ironclad contracts with BP, and they do not have the option of switching who they buy oil from, or whose name appears on the sign for many years to come.
Furthermore just because people enter a contract with Exxon, does not mean you will get Exxon oil. Trade agreements between oil companies are everywhere. As I understand it, there are gas reserves in certain spots across the country. If you own a gas station, and have a contract to use Exxon gas, but your station is 1,000 miles from Exxon's reserves, and 50 miles from BP's, you will be getting 100% BP gas, even though you are under contract with Exxon, and vice versa. So my point is, money is still going to BP through these trade agreements.
Also here's a good article on why all gas companies pretty much suck anyways (though I still personally think BP is one, if not the worst [yes, I actually hate BP, too]): Boycott BP! Because it’s much better to give your money to Exxon.