Q: when i start to update ios 10 the code changed,now my phone is locked

There is nothing they can do about the passcode lock. That only exists on the device, and does not change when you update the phone. You may be referring to Activation Lock, which cannot be bypassed. If you are speaking of the passcode, the only way to remove that passcode is to restore the device to remove it, and then you restore your backup. The responsibility to backup the phone is yours and yours alone. If you have not backed up the phone in a year, you have been extremely lucky things haven't failed yet. You should be making regular backups of the phone, and with iCloud backup activated, it will automatically backup the device whenever you plug it into power, it is connected to wi-fi and the screen is locked. This support document will provide instructions on how to restore the phone to remove the passcode. If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support