What if the lock breaks not long after delivery?

If it is found that the lock is broken soon after delivery, you can follow the following steps:

1. First, you can contact the property and tell them that the lock is broken. They may send someone to check and decide whether the lock needs to be replaced.

If the property doesn't help, you can contact the developer to see if they can provide a solution.

If the above can't help you, you can consider changing the lock yourself, or find a professional locksmith to help you.

Finally, if you find that there are warranty clauses about locks in the purchase contract, you can seek solutions according to these clauses.

In short, you should take action as soon as possible to ensure that your safety and rights are guaranteed.