This is probably why my HDFC bank RM told me to come to branch and avail the pre approved offers. As in, many times we may not know what exactly details to put in for smooth card approval. The bank people sometime know better as to how the offers will not be rejected.
Maybe, if possible, you could go to branch and tell people there to fill out the details for you. Whenever possible, I do this, because they often know what exactly to put for smoother processing, lesser chances of rejection.