If you reboot your phone, you will not lose the contacts, but also you will not unlock the device. If you have Internet access, I suggest you install Screen Lock Bypass Pro from Google Play Store. It will bypass the lock screen and reset/remove your screen lock password, pattern or PIN number. If this doesn't help, you will need to factory restore your device using the instructions from the user guide. This process will erase all contacts, media files and customized settings from your phone. Basically, in order to restore the device to its factory condition, you will need to turn it off and to press Volume Up + Power buttons. Using the volume keys select Wipe data/Factory reset from the Recovery menu and press Power.
Note: After you factory reset your device, you can recover the contacts only if you have saved them on your computer or to a cloud service.
