Messages

If you were syncing Messages with iCloud and you deleted the messages, they can't be recovered. If you weren't syncing Messages with iCloud, do you have a backup you can restore from? Restoring from a backup erases all data currently on your device. Any data newer than when the backup was made will be erased. A restore is an all or nothing restore. You can't access a backup and only restore certain files.

Backup - Restore your device from an iCloud or iTunes backup.      

Latashalocke wrote:

I

You may think this is cheating the system to get points, but you’d wait to know this is not allowed, and it doesn’t work.

As Eric said, you’re messages cannot be recovered. Unless you weren’t syncing from iCloud, do you have a older backup?

More information at https://support.apple.com/en-us/HT204184

Cheers!