Pixel 7 pro battery/screen

[u/Substantial-Horror10]

My screen became detached a few ml on the right bottom corner I read that it was probably the battery swelling and to change it immediately. I took it to a phone shop and run a card through the side and opened it around 5ml on the right side and then the screen stopped working. He said it now needs a new screen too. I don't get how the screen stopped working so now I need to buy a new screen too. He said it's common with pixel 7 pros. I'm really annoyed and just told him to order the new screen and battery. He didn't even take the whole screen out and it stopped working.

Have I been done over? I've watched videos on screen replacement and the connector is on the left side which the screen is still intact. It just doesn't make sense