To be honest it is a liability. The tank is an easy swap through the storage compartment. You can leave the lines connected to the fuel baffle, take the straps off and leave the oil tank in place. Just button it up, keep your tank out drive it up there and let them do the work. For what they get paid labor wise to do it from BRP, they will lose money. Let them lose their money and you get your new tank. Just tell them it's going to be a month or so and you'd like to come back and wait while they do the swap. Walking out threatening to sue was probably the worst thing you could have done, not to mention you wouldn't have a leg to stand on since you know that the tank is defective and they have a tank there married to your HIN.