WEll don't hold your breath. . .I've worked in campaigns as well; the sheer volume of calls and mail preclude 'replies'. Why don't you just pay a visit at campaign headquarters. . .or your Congressman's office; go to the 'coffee's they hold, where they 'make time' for their constituents.
Beyond that, to expect a 'reply' goes beyond reasonable expectations, IMHO. . . and why, in these venues, would you expect them to have the time to pen a letter off; when they receive thousands!