How can I save my locked iPhone 16 Pro Max when someone hacked it?

Your phone was not "hacked". You got conned into giving someone the credentials for your Apple account or you got conned into logging into the device with someone else's account.

Your only option to have the activation lock removed is to present Apple with the original proof of purchase from Apple or an authorized service provider.

if you don't have that, you may as well recycle it. There is no way to bypass the activation lock.

Re: “I sent all the purchase receipts in my name to Apple support many times but they refused me many times. Do you have any way to help me remove the activation lock? Please help me.”

There is no way to bypass Activation Lock. If you have let scammers lock the phone to their account, and Apple refuses to remove the Activation Lock, it’s game over. The only help we can offer is to advise you NOT to pay the blackmail … and to avoid falling for this scam when you get your next phone.

chinh89 wrote:

I sent all the purchase receipts in my name to Apple support many times but they refused me many times. Do you have any way to help me remove the activation lock? Please help me.

No one here can help you and if Apple refused to help you, it's hopeless. You'll have to buy a new iPhone and hopefully, learn from this unfortunate experience.

chinh89 wrote:

I sent a request to apple support but they rejected me

In that case, it's a paper-weight.

Recycle it and take this to heart as a life lesson.

Even proof of original purchase may not be sufficient if the scammer has put the phone into Lost Mode (which seems likely).

Apple’s Activation Lock support request page says that the phone must not be in Lost Mode.

In addition to what has already been said, you should be prepared for Ransom threats. And if you pay whoever you let take over your phone, they'll most assuredly ask for more and more. You're in a losing battle here. It was really most unwise of you to let someone take over your phone. But it was you who did so.

Thanks for pointing that out. I didn't realize that. Is that a recent change?

Re: “Is that a recent change?”

I don’t know when Apple added that; just that this is what it now says on one of the Support pages.