We got a Hyundai I20 Key for repair. Keypad of this key was torn-out and customer had found a unique way to fix that. He inserted a small metal ball bearing in place of holes left after removing the keypad. He found a perfect size of ball bearings which fit perfectly in those holes.
Although a cheap fix, but its not recommended for regular use. On close watching you can find that there is little gap left between bearing and plastic casing which allows dust and water inside. On prolonged usage this may also result in damage of remote circuit. Its recommended that you use replacement keypad instead of this cheap-fix.