I'm sorry, but Apple does not provide a downgrade path for iOS. Because downgrading is unsupported by Apple we cannot discuss it on these forums.
You may leave comments at Apple Feedback.
Have you tried any troubleshooting?
Restart: Press On/Off button until the Slide to Power Off slider appears, select Slide to Power Off and, after It shuts down, press the On/Off button until the Apple logo appears.
Reset: Press the Home and On/Off buttons at the same time and hold them until the Apple logo appears (about 10-15 seconds).
Restore: Connect your iPhone to iTunes on your computer, backup, and then select Restore to Factory