Opening Trunk

I've Just Bought 03 Sel found out at the mall that the trunk does not open with the key put it in does not turn;does not open with the remote key opener all other doors open,It opens with dash button! and one back door does not open from inside with or without child lock on or off anybody got any hints? thanks

Back door: linkage to the interior door handle may not be connected. Someone may have tried to open the door from the inside at the same time someone was trying to open it from the outside (kids) and stripped the gear to the interior handle.
Trunk: Have you tried using the key before? You may not have the correct key (something may have been changed) or key is worn (unlikely since car is only a year old). Do you have more than one copy of the key? Remote may need programming. Do you have the owners manual? The person at the Ford dealership parts counter may be able to help for the price of windshield wipers.
Where did you buy it? Is there a warranty? Do you know the previous owner?

Kim took the door mech off today the latch mech from the door inside handle was screwed up it was not tripping the opener spayed it and by working it back and forth it freed itself.working great now!going to check dealer about key and remote.car is not under warranty 130km company car guy who drove it never use the key to open the trunk and nobody ever sat in the back seat thanks for the reply