All purchases are considered donations towards the upkeep of the server, not for in-game items, and are non-refundable. All badges are able to be obtained in-game through various events and games. Badges can also be given out for free for being an exemplary community member, helping coordinate or creating events, participating in Server Saturday, etc. 

If you donated and didn't receive anything in-game check /cr claim. Your inventory was probably too full.