If you have your keys with you, but the lock on the car door is broken or doesn't work properly, you can try to enter the car through the trunk. Not being able to access your car can be a valid reason to call the police. However, they may not be able or allowed to unlock the car unless it's an emergency, such as a small child or pet locked inside. Even so, without specific tools and skills, they're likely to have to break in just like you would.
In the case of non-emergency lockouts, the police will normally call a car locksmith or a towing service, but you'll have to pay for it. While comprehensive insurance covers damage caused by theft and when your own car is stolen, it doesn't cover personal items that are stolen from your car. Highway insurance can also cover towing costs within a specific radius if a locksmith has difficulty unlocking the car due to new technology, a faulty lock, or other problems. If your car doesn't have those types of locks, the good news is that there are many easy do-it-yourself methods to get back into your locked car.
With this tool, air is pushed between the car doors to create a door opening large enough to use tools and to be able to effectively unlock the car.