Iphone 5c problems!

Hi, So basically I was out today at a restaurant and i had a discount code on my phone so i handed the waitress my phone and she dropped it. She gave me the phone back but now my screen is very dark and I'm getting screen ghosting/images are burning in. Now the manager at the restaurant said he would fully pay for my repairs or a brand new phone if it was unrepairable.

Now the problem is i replaced my screen, myself, a couple of weeks ago so im guessing Apple wont fix it if it has been tampered with.

I was wondering what peoples thoughts/suggestions were

Much appreciated.