How solve this problem?? gas guage

I have taken my GT to the Local Ford dealer ship Twice so far and they are completely uneducted. I had a minor spin out a couple months ago and when I got the car back I noticed that the Gas guage "low gas" light came on. I filled the gas tank up and the pump stopped at 11.5 gallons. Wierd but i thought nothing about it (3 month down time). Week later The low light came on agian so that told me that it was about 13 gallons. When I filled up the pump stopped at 12.2 vise 14.2 as I expected. I got suspicious and waited one more week. This time when The light came on solid I filled the car up and DING 11.58 gallons. So I took it to the dealer ship and told them the problem.

They used the eletronic detector it sayed no problems. I said They looked at it again and they replaced the fuel sender assy. So I took possesion of the GT and guess what . . . ANYBODY . . . It still there.

So I took it back and they said there's nothing Wrong. So they said they can pull the tank and check something but It would cost ME. I said And I left.

So now I need some suggestions on how to deal with this problem. Oh and saying going to another dealership. . . well I live on GAUM. . . one dealership on island. I believe it has to due with the leveler or probe that sences the lvl in the tank or it is off allignment. But am not to familiar how gas guages work in cars.

Anyways, i would appreciate any help.

well the light should light up at about 13 gallons right? well mine lights up at about 11 right now. I know that its fault due to the distance to gas light are now constantly wrong. Also, i know how far i can drive until the tank is near 14 gallons.

This is the result of the spinout.

http://forums.stangnet.com/showthread.php?t=592813

But still i'll try to look at eh ank but the dealership said and repar facility said tank was undamaged. But right now 1/4 full is 25 mile 1/2 is 50 mile 3/4 is 80 miles empty is about 145 miles.