A lock is a metal mechanism with moving part and mostly with a daily usage, eventually wears out.
To your question what should you do if the lock is damage , you should consider change lock at your earliest opertunity.
As this lock may still work with some difficulties like, key that sticks and hard to turn or door handle that doesn’t operates properly . you may find yourself lockout out of your house one day as all part will failure to unlock. This requires a locksmith call !