RustBucket

iTrader: (1)

One thing to consider is that when the original bolt was installed it was obviously overtightened which is why you had trouble removing it. It's quite possible that the crack actually happened right then (might have been why there was a small leak in the first place) and the removal of the bolt and installation of the new one caused the crack to open up further. Many aluminum oil pans have this sort of issue because the drain bolts are replaced many times and fatigue the soft aluminum threads. Obviously if this is the case it doesn't give the dealership the right to be rude to you or to charge you exorbitant rates to fix your dilemma, but they may not be 100% responsible.

If it was me I would find a machine shop and ask them to TIG the bolt hole, clean the threads with the correct tap, and call it done. You could even use a fiber or rubber washer in place of the aluminum one in order to seal the hole with less torque on the bolt. That is a common practice on various Honda aluminum oil pans. The aluminum washer takes 30 ft-lbf to seal properly and a fiber one might take 15 ft-lbf. Hope that helps.