Work out which kind of rejection it is
There are only three, and they want completely different responses.
- Fixable: a thin description, a broken link, the wrong category, an unreachable contact. Fix the thing, resubmit, done.
- Structural: the directory is for a category you are not in, or an audience you do not serve. Nothing to fix. Stop and find a better-matched directory — this is a good outcome, cheaply obtained.
- Disqualifying: the site sells link placements, is auto-generated, or is in a category the directory refuses. Resubmitting will not help, and the underlying issue is worth taking seriously because other directories will reach the same conclusion.
How to ask why, so you get an answer
Keep it to three sentences: what you submitted, that it was declined, and a direct question about what specifically to change. Reviewers answer that. They do not answer long appeals arguing that the decision was wrong.
If a directory will not say why — or has no reachable human at all — that is useful information about the directory. A place that declines silently and sells paid listings is running a different business than the one it advertises.
The resubmission
Change the thing they named, and say in one line what you changed. That single sentence moves you from this again to they listened, which is most of the decision.
Resist the urge to also rewrite everything else. If the second attempt is unrecognisable, the reviewer is starting from scratch rather than confirming a fix.
When to stop
After the second decline on the same grounds. At that point the cost of further attempts exceeds anything a listing on one directory is worth, and the time is better spent on a directory that fits, or on the underlying problem they keep naming.