Tank Assembly problems of the 2011 Ford F-250

The def tank continues to throw a check engine light warning. According to the dealer Ford knows about the problem and there is no current fix to the issue. My def tank was replaced with a unit off another vehicle on the lot and was told that I could be left stranded if the light continues to stay on. San tan Ford had no fix for the problem until Ford release a fix and according to the service manager there are 120 people waiting for tanks. How can Ford continue to sell these f250's if the def tanks are not working and leave the vehicle out of working order. This is a serious safety issue if the vehicle disables itself at anytime due to this problem! there needs to be some pressure put on Ford to get these vehicles in working order and people should be made aware of this problem if they are spending over $50,000 on a new vehicle that may at anytime stop working with no fix available. Need to recall ASAP, people all over the forums are complaining of the issue and removing these pollution equipment to have their vehicles working correctly. Not good business Ford!.