When having problems with locks I usually have 3 options - since I run a fleet of cars and rent/lease them out I deal with these issues all the time.
Dealership Warranty -If the car still has warranty then back to the dealer she goes. But if they argue and say they cannot fix it due to wear and tear you can always argue back that you noticed it before but never reported it. It's a 50-50 battle, depending how you argue it out with the dealership.
Locksmith - Locks are usually the forte of locksmiths, getting into house door locks and car doors s their speciality. Even if you need an
emergency locksmith thamesmead they can help you out 24/7 right at your door step.
DIY - Read up on your locks. pen up the door card and get your hands dirty. If you don't own a high-end car then this method can save you bucks.