Tank Mounting problems of the 2005 Chevrolet Venture

I have a 2005 Chevrolet Venture Mini van that has developed a fuel leak around the area where the filler tube connects to the fuel tank. Having researched this, it is apparent that this has been a problem for these vehicles as early as 2003. This the third time this has happened on my van. I have attempted to repair it twice, using an epoxy sealer,but the leak redevelops after a few days. I might have to replace the fuel tank and filler tube, if I can find one that I can afford. Gm says that this is not defect and will not issue a recall, but it seems that just the idea of fire hazard would be enough reason for gm to fix the problem. I do not see how gm can not say that this is not a defect in the design, since this has occurred a number of time. It's a plastic side mounted tank with no protection surrounding it and a filler tube that joins it in a very vulnerable area.