Tank Assembly problems of the 2001 Hyundai Accent

Gas was leaking from tank to the inside of the car under the back seat around the plate that covers the fuel pump. Gas pooled underneath the the back seat on passenger side. When seat was removed the foam on the underneath side was saturated with gas and from the top of the seat you could put pressure on the seat and gas would literally leak out of the seat. The week before our grandchildren were in the back seat and we all were complaining of headaches. The smell is still there after 2 attempt of the car dealership spraying it and ordering a new back seat. We feel like we should have a new car out of this because it is not fixed. This could have been so dangerous. The person at the dealership told us we were very lucky people. If we had smoked or someone threw a cigarette or match it would have exploded. Also he said after the plate got so full, it could have gone back on the exhaust and it would have blown. When I think what could have happened it makes me sick. My only hope is there is not another one out there like it because it could be very dangerous. This car should never have made it off the line. This makes me think that they do not inspect their cars very well if one or more got by with something as dangerous as a gas leak.