While I am not a lawyer, I do believe the shocks should be covered under the dodge warranty for failure after 5 months as its got to be a defect in the manufacturer. (unless you been our racing)
Ran into a similiar problem with a Toyota, where dealer wouldn't replace a shock that blew out after 3 months. Took a call to toyota corporate to get things fixed, but it turned out dealer was "misinformed".
You have rights under the warrant of the vehicle, and Chrysler actually is pretty good if you contact them after getting no where with a dealer. Your rights under the warranty and what it covers is listed in the warranty booklet, which if you don't have can be downloaded from ramtrucks.com
I would ask the dealer to point out where it the warranty it states the shock is not covered under the basic limited warranty. As I have been through the booklet an I see no exclusion for shocks/struts. Dodge even covers consumables like brake pads and wiper blades for 12months/12000 miles. So unless you got over 12,000 miles on the truck already am not sure where the dealer things its not a warranty item. In the warranty booklet there is a procedure and numbers to contact in case you can't get the warranty issue resolved with your dealer.
Of course that is just one man's opinion.