2001 back hatch stuck?

have 2001 nissan pathfinder with back hatch stuck in lock position. fob and key work for other 4 doors just not the back. used to hear back hatch lock and unlock but hear nothing now. when i use key in the back i can turn it clockwise and it functions (all doors lock and window opens, no prob) but when i turn it counter clockwise it is hard to turn and only a couple of times did all the locks unlock, except the hatch. sprayed lube in cylinder but no such luck. the 2 key holes i have ,front and back, control all locks.cant open from inside or find a way into the back panel.need help, any advice will help.