Batteries Plus Repaired phone incorrectly, refuses to warranty. Chico California

I brought my phone in to Batteries Plus on June 28th for a screen replacement. I received my phone on the 29th and all was good until July 30th, two weeks later. I took my phone out of my pocket and saw that there was a hairline crack going from the right top zigzagging down through the home screen. I called and told them my situation and they said they may be able to warranty it When I got to the store, the rep inspected my phone and pointed to where the cracks split.He informed me that these were impact marks, and I obviously damaged the phone myself. It had been in a case since the repair, and I know for sure it was not dropped or damaged. They refused warranty at that time. When I got home, I talked to a few people I knew who worked in the mobile repair industry. For one, they told me that the damage did not look like it was from an impact and there were no impact marks. They instructed me to inspect the seam between frame and screen, as I hadnt taken the case off yet. The top right corner of the screen was lifting up off the frame. The glue had obviously failed. I was told that with the screen not correctly held in place it would break more easily under NORMAL OPERATING CONDITIONS. I went back in on monday, and spoke to the manager about the situation. He informed me that were indeed impact marks,and the screen lift was NORMAL! They once again refused to warranty the work, although the warranty covers WORKMANSHIP. I am extremely displeased by the lack of ownership for mistakes, and the terrible work quality. In addition, in my research on the screens they use, I found they use questionable screens, that they say are "new", but contain refurbished parts. They are also not OEM spec.