That doesn't seem right
Uhh, this isn't bad....
~1 1/2 hours with ~15% battery used. That's heading toward 10 hours of usage. Getting 10 hours of usage is quite the feat with an iPhone. While not impossible it's very rare, you can do it with locally stored music playing in the background (screen off) but don't expect it from the way you use the phone.
Hence why Apple didn't find a problem. With my usage patterns the best I've ever got on any iPhone was 7 1/2 hours.