BP wasn't great to deal with, but the real issue wasn't with them. In a nutshell, dad rented the corner lot from a local oil company, who leased it from a local group of realtors. So, you have dad, land owners, franchise group, and BP. Too many hands in the pot, and not enough dough to go around.
The place will either be turned into a full store like a Duke and Duchess, or --my guess-- it will be leveled since the building is from the 50's, so it has older wiring and mechanicals.