Particularly, your Facebook account hacking is not a hard thing for a smart hacker.
In case, if your Facebook account has become victim of hackers, here is a link and feature to regain the account again.
The features is separate for various devices. They include mobile phones, which are not smartphones, iPhones, iPad, Android devices, Mobile Browser, and many other.
Just click on the relevant device, on which your account has been hacked. The click will lead to a page where Facebook will ask you to password.
Just enter the password and follow the instructions, you account will be recovered within minutes.