In order to unlock your device, I suggest you install Screen Lock Bypass Pro from Google Play Store. It will allow you to bypass the lock screen and reset/remove your screen lock password, pattern or PIN number. If it doesn't help, you will need to perform a factory reset. To do this, press Home + Volume Up + Power buttons and from the Recovery mode menu, select Wipe Data/ Factory reset using the Volume keys. Once the process is complete, restart your phone.