iMessage on iPod Touch 4th Generation

Hey fellow apple users,

So I bought my iPod Touch 4th gen in January, and I activated iMessage. However, periodically, or rather, nearly every second day, iMessage seems to quit working and will NOT send or receive messages. I have tried shutting off/turning on both my iPod as well as iMessage in settings. I have switched the DNS to 8.8.8.8 and have even restored my iPod to factory settings and re-activated iMessage. Nothing seems to work, and it's getting fairly annoying, seeing as it will quit on me for days at a time. Any suggestions would be very much appreciated!

Thank-you,

Simone