Got blamed by a customer because they forgot their iPad password

I work at a specialty retail store and one of the services we offer is device repair, older lady dropped off an iPad mini for a new battery and probably a new screen (the screen had some minor cracking so 50/50 we could get it off without making it worse, so we quoted the price of a new screen as well).

During the check in of the device we ask for the passcode so we can check everything functions; camera, wifi, speakers, and microphone. Customer declined which isn’t that uncommon.

Repair goes well, screen did get damaged so that got replaced. Customer picks it up and takes it home, she comes back about an hour later and starts yelling at me we changed the passcode.

She had disabled the iPad for an hour because of too many failed attempts to login and it was of course my fault.

I explained to her that since she declined to give us her passcode it was impossible for us to have changed it. (Anyone who works in device repair knows if you mess something up with a device it’s usually catastrophic and doesn’t work at all)

She wanted a discount or her money back which sure as hell wasn’t happening, I’m also the assistant store manager, so I told her we aren’t responsible for her getting locked out and the only way she’s getting a refund is if I put the old non-functioning battery back in and the cracked screen back on.

Did a literal huff and stomped out. Haven’t seen her since