Find somebody other than the person who "brazed" it. A good braze job (properly prepared and brazed) would not have failed. Find somebody who can weld, braze, or otherwise repair it properly. Cast iron welding is a real art, and few people can do it right. Preheat, weld with nickel-alloy rod, post-heat, and peen the weld thoroughly while it's cooling, then bury the part in a pile of sand overnight to S-L-O-W cool.
Jerry
