Your options are to return the presumably iphone, or keep it, or ask to get one that has genuine parts. That would be trickier. If the screen is OLED, I wouldn’t care. But they’ve often used LCD screens to fix what should be spec’d OLED. I wouldn’t care about the battery either, but you lose a battery health indicator feature by having a third party battery. So it depends on what you’re personally ok with on how to proceed.

The screen seems off to me and lags a lot we all have iPhone 11’s here 

When you said it was off, what happened? if you are within the 30 day period, you can always return the phone.