I received a letter by mail stating I'm only eligible for a certain portion of my full GI Bill benefits. I was medically retired (honorable discharge) with 100% service connected disability (TDRL). I called the GI Bill help line and they said that because I'm on the TDRL I don't qualify for full benefits. Then the guy suggested I "get it changed to permanent", as if I have the ability to go ahead and "upgrade" a disability. Is this true?