Hey there! I didn't reject the first time, so I can't answer as to why the ad wasn't accepted that time - I didn't see it. I did reject this most recent one though, for the following reasons:
As per the rules (which I didn't set, I just follow), games with storyline comms are not allowed. Judging by your comment it sounds like this might be the reason for rejection the last time?
The big one, for me, was that there was no information in the ad. In the rules it says that ads have to have content, not just images or one-liners. So that was why I declined the ad.