I was locked out of my Apple ID

yeah, that's what I've read the first time. Your device is now activation locked to the Apple ID of the scammer. That's why you cannot login with your own Apple ID anymore. Thus, you will have to start an activation lock support request at apple. That is the only way to get the lock that the scammer placed of your phone. In order to do that, you will have valid proof of purchase information (which you have, luckily) The police report can also help in this process, with that you can proof that the Apple ID that is currently on your phone, is the one from a scammer. To get started with this process, please see this link: start an Activation Lock support request.

I am sorry this happened to you. Please report this at local law enforcement. After that, if you have the original proof of purchase information of your iPhone, toegether with the report from law enforcement, start an activation lock request at Apple

 start an Activation Lock support request.

Hope this works for you!

I would Contact - Official Apple Support If I where you to discuss your options. This is a user to user forum and apple is not actively participating here, so there is only so much we can do.

It is also important to get in contact with local law enforcement, maybe they can do something for you.

Again, I am really sorry that you're in this situation

Anytime! I hope this problem gets solved soon for you!