NZ Couriers Forged Signature

I ordered something online the other day which was posted through NZ Couriers. This morning I checked the tracking to find it had been delivered into the mailbox which is down a long driveway, that parts all fine. However the part that grinded my gears, down below the tracking number showed it had been signed for not just with ATL like NZ Post sometimes do but as if I had signed it with my name and all. I signed nothing, there wasn't even authority to leave placed for the package. What happens if the package went missing but shows I signed for it