IPhone XR screen replacement and problems

I don’t know much about phones but wondering if someone has any help or advice for me.

I had my XR phone screen replaced (not by apple) after it had a tumble down the stairs. Apart from the cracks in the screen it worked perfectly fine. I got the screen replaced as I hated the few cracks across the screen.

after I got the screen replaced I could no longer drag down the control centre (I think that’s the right name, in the top left corner) or use some buttons for example the next button on Instagram pics. And a few times the screen went black and after maybe 6 times I worked out it came back on when I pressed the screen slightly.

i took the phone back to where the screen was replaced. And they said it was software issue with ios13 and ios14.

today I had black and white lines on the screen and I took pictures on another phone. I took screenshots on my XR thinking it would show the lines but it showed my normal screen as it would look without all the lines on.

I’ve attached pics and of anyone can give me any helpful info I would be very grateful. Thank you!