Here is what they said (at last an answer to a question I sent):
"If you send me the image IDs, I can delete these for you as long as it's not an unreasonable amount of images. No one can see the rejected images but you, so I'm not sure why you want to remove them."
So... basically they don't understand why someone would want to remove rejected images. I am just wondering why they do everything to keep them? Now I have to send the ID of each rejected ones, and if they are too many, forget about it. They keep them!
It doesn't make sense to me. It's my right to remove the rejections from their system, no?