im cam, a licenced diagnotic and alignment tech.
have you had your steering dampner checked or replaced?
these dodge trucks have always been known for steering wander and sloppy steering.
the box can also have excessive play causing the steering to give you that feeling.
im actually suprized that you have had it to alignment shops to do an alignment, and they actually hand you back your keys with the same problem instead of telling you that there is an issue and they will have to dig a little deeper to find the issue.
i would never hand a vehicle back like that.
the only reason that the alignment would go out everytime they check is is something is worn or loose in the system.
these components must be checked
1. the steering dampner shock if equipped.
2.complete front end inspection for loose or siezed components
3. the steering box. any lateral movement in it will cause horrible steering feeling.
somebody is missing something and is going to require a reinspection as alignments just dont go out for no reason
let me know what you find!