Key will not open doors

Manually operating the key in the door will not unlock the door, it feels like its not connected to anything. the remote central locking has never worked so we have had to manually enter the car using the key. there is no key hole in the passengers door. My question is how can we unlock the door or gain entry to the cabin to unlock the door from the inside to operate the door release button located in the centre console. Or how do we break in without damaging anything