Tank Filler Pipe And Cap problems of the 2004 Chevrolet Express 3500

Gasoline and gasoline vapor was escaping from the fuel filler pipe leading to the fuel tank on a 2004 chevy express van 3500 series. The filer pipe was rusted through. There was a seam on the pipe where the rust through occurred. Gasoline was dripping from this hole during gasoline fill up and vapors were entering the passenger compartment. We had it replaced by a certified mechanic because it was a potentially explosive situation, according to the mechanic. This was reported to gm. There was no recall on this part, so gm refused to pay for the cost of the replacement part and labor. The replacement part is now plastic. So gm must have recognized the problem (but failed to recall) and changed the pipe to a rust-proof material.