Call the dealer up and explain it to him, it sounds like the rod from the lock to the handle might have come off, that would explain no tension when you try to lock and unlock from the inside of the drivers door. as far as feeling safe if only the drivers side wont lock, park that side close to your home(or something else) to block the drivers door from being opened, then just exit through your passengers door and lock it up. Ive ran into this problem more than once and its usually the rod has become detached from the mechanism, dont let the dealer screw ya either, watch the repair if you can