I think you have too much at stake here, not to talk to a lawyer about this as soon as possible.  One place to find a qualified attorney near you is our website, http://attorneypages.comThere are some important factual details that your lawyer will need, to give you reliable advice, such whether the pump is actually in your home or your neighbor's.  It sounds as if your house will be uninhabitable if that pump isn't working, so I would think that there has to be a way to keep it on.  But there is quite probably a right way, and another way that ends up being much more expensive.