I guess I'm bored.
If it were me:
Poor/no response, important pieces missing, unwilling to return = negative feedback.
Poor/no response, important pieces missing, willing to return = SNAD, then (not positive) feedback depending on how it's handled afterward (pieces sent, partial refund, return all valid possibilities)
Poor/no response, minor pieces missing, unwilling to return, new/good feedback history = negative feedback
Poor/no response, minor pieces missing, poor feedback history = SNAD to help weed these people out
Cooperative response, important pieces missing, new/good feedback history = neutral or no feedback
Cooperative response, minor pieces missing, new/good feedback history = positive feedback with mention of issue
Cooperative response, lame feedback history = neutral feedback