I have locked myself out of my Samsung Galaxy S5
I think there is a way to remove the lock. While I don't own this particular phone, you can flash Aroma File Manager to the phone by copying a zip file containing the manager to your external SD card. Boot the device into recovery, and then install the package. Go into the system files of the phone. There is a file somewhere called password.key or pattern.key, depending on whether the lock is a pattern or pin/password. Delete it. If the system files are not showing up in Aroma, make sure the device has mounted the system files in options. Reboot, and the lock should be removed.