Yeah really weird situation and should never happen. I want an explanation about this whole thing and I hope they don’t just push it under the rug and stay silent. It has really put me off of even logging in this Christmas. Getting a submission accepted (even if it was made by someone else for me) is still a huge deal and having that just taken away sucks.
I actually had the chance to talk to Xenethes on graal earlier and the explanation as to what I was given for why people were receiving rejection emails was for "copyrighted or stolen content". This information might not relate to what happened in your situation. A friend of mine and I are going through the same frustrations and confusion as you are with receiving an acceptance email and then a rejection one. Sadly enough we will probably never receive a full explanation on the reason as to why.
It truly makes me mad in the aspect that I spent 350k to max out on gifts to not even get the hat my friend made.
Also, I would like to say that there is still uncertainty in if you submitted more than one hat if all your hats were denied or not. As no one really knows what exactly was accepted or rejected. There could still be hope if you received the rejection email. Just tryna put a little bit of positivity in this situation.