the ones talking about the switch are right about how its suposed to work, but my guess is that you know that… from what you said it sounds like your door is broken as the others have said. i think you will need to take it to a dealer.

Broken

The switch is inside the rear doors. Flip them the opposite direction to disable this feature

D B Cash has the right answer. when you open the back door the latch mounted to the door has a small switch on it and you can FLIP this switch or lever and disable the child safety lock system. It’s not broken, listen to D B he’s telling you the right way to do it

My car had those and it had a little switch on the door (the part that you can’t see when it’s closed) by where it latches. You just had to move it over.

there’s a switch inside the door, use it!
hard to miss

If you can get the door open there should a switch near the lock mechanism

needs a new lock/latch assembly you need to remove the ddor panel to do this if you never have done this dont and even if you get the door panel off without mangling it you will probally wish you took it somewhere after you cut the hell out of your hands

As in almost every car, you can find the child lock selection in the back door, it is a little switch.

you cant
there broken
needs to be seen at a dealer