Should I replace my battery or see if my issue is covered as a defect?

My screen has been having poor responsiveness. I'll go to swipe and it will either be unresponsive or it will go haywire, selecting apps I didn't select, typing things I didn't type, or just generally going on the fritz. I had been able to mitigate the problem by running my fingernail around the perimeter of the screen to raise it from the casing.

I just found my screwdrivers for past parts jobs I have done on my Macbook Pro and iPhone in the past. I opened it up to confirm my suspicion: my battery has a small circular raised area on it that appears to be a defect. The raised swell with a diameter of about a millimeter had been pushing up on the posterior of the screen. This pressure has been what has been creating the issue.

So my question is: is this a battery defect that I can cash in on for a new phone or is this something I should just replace?