Hello Kwami12,
Thanks for asking the Apple Support Communities about your TV Remote.
Not sure what caused that damage, but the only service available for the Apple TV remote is the battery. This damage would require you to buy a new remote, or just use your iPhone with the built-in Remote app.
Set up the Apple TV Remote on your iPhone or iPad - Apple Support
Be aware, the new Siri Remote looks different, but is still compatible. If you want the same remote, look for an official reseller.
For cases, look at retailers like Amazon, Best Buy, Walmart, etc. Many make some sort of cases to help protect them, but we aren't aware of one that would protect from such catastrophic damage. Here in no special order are three examples:
Thanks.