Accidentally deleted my message with the Beta code

So unfortunately i deleted the message with my beta code. Here is what happened
I was in the middle of a match, received my invite. Redeemed the first code and started the download and went back to my game. I did NOT read the message
I did see there were two codes but i generally assumed the second code was for a friend or something so i left it alone. 3 hours later Halo 5 Beta finishes downloading and I try to play only to be stuck at the screen saying it launches on the 29th i said that cant be right and went to the Preview app and read that the second code is to actually access the beta. I go to my messages and low and behold the message had been deleted. Now i didn’t do this on purpose nor did i do it my self. My nephew plays my Xbox 360 but on my account so he too can see the messages. He often gets rude messages from other Xbox live players so i tell him just to disregard them and delete them. I assume he deleted the Xbox Live Message with my access code. So as you can see im in a pickle here. If anyone can help id greatly appreciate it.

I spoke to Xbox Live support and they directed me here.

Lol, did they really? That’s hilarious.

> 2535425310804235;2:
> Lol, did they really? That’s hilarious.

I know. It sucks