Tank Filler Pipe And Cap problems of the 2003 Chevrolet Express

Since October of 08, I ordered a filler tube which allows the gas to travel from the gas cap to the gas storage tank. Everytime I fill up, gas stations will shut the pump off due to severe leaking from this filler tube. The leak is so severe that the fear is somebody dropping a cigarette at the time of fillup. Approx 1 gal of gas leaks/ fillup. I ordered the new part in late October from the dealership I purchased my 2003 chevy passenger Express van. I have spoken to the chevy regional office and been told that the part is only available at 5 dealerships in the country but they have been reserved for customers and I would have to wait until the part gets manufactured once again. When? they don't know. I requested a similar vehicle be loaned to me until the new part becomes available. They said "no, if you feel unsafe then I shouldn't drive it. I told them this is an accident waiting to happen and it will not only cost my life but anyone in proximity to the gas station. One particular dealership shared with me that if gm doesn't pay a bill for whatever reason, the part manufacturer halts production and this is what happens. Will you please help me?.