You can change them back by going to the "Frickbears3" folder in your AppData folder, opening your save as a .txt file and editing the settings values manually! If you wanna restore the default controls, replace everything starting from "_Settings" to the first comma with this:

"_Settings":[[32.0,27.0,87.0,65.0,83.0,68.0,83.0,87.0,65.0,68.0,90.0,88.0,32.0,16.0],

A proper fix will be made for the final game, but hopefully this'll do for now!

ADDENDUM: You can also just delete the file, a new one will be created the next time you play the game with the default control settings. This will also delete your save data, though!