The dish company has a responsibility to look at whats on the other side of the wall befor they drill. Thats common sense. They should replace whatever they damaged because the employee is at fault. A 500gal tank is not cheap either, I hope you still have a reciept. I would damand a refund of my broken property or i would threaten to take them to court. They will pay up
Thats over 4000lbs of water. It probably wouldnt break, but i wouldnt trust it. Thats alot of water in your house. I say they owe you a new tank.