Chuck's answer is correct some how the lock has jammed if there is no blown fuse the push button switch should work unless the electrical plug to the lock in the trunk is unplugged and as for the key do you feel any thing when you turn it is it a little bit resistant when you turn it/ is it very loose / or press down on the trunk while turning it do you feel any click in the key ? Also is the trunk a little loose / does it move up/ down more then it should if so the inside lock mount is loose/or the locking pin on the trunk frame has moved from slamming it to hard the bolts came loose rocking it up/down may get it to release but if not what Chuck has said applies here you must take out the back seat or fold down if equipped and go in the trunk with a flash light and a small ratchet set remove the plastic frame/ cover around either the trunks body mount for the locking pin at the bottom or the lock itself on the trunk lid there is also a glow in the dark safety release that you can pull on but if that lock has failed or something is jammed into it this will not work so try the easy stuff first pressing down on the lid or trying to rock it to free it up otherwise getting in the trunk from the back seat is the easiest and cheapest a repair shop will do the same as I just described only they will make you pay when you could do it yourself for free