do you mean it locks using key but wont unlock with key? this is how they are meant to work if a wrong key is used. it may be just that your key is worn,have you a spare key ,if so try that this is the usual cause of your fault.
k
January 2013
Have you tried googling it? if u have and it no help try ur manual if it no help contact ta company see i no have ford ka!
almera lover
January 2013
If it locks & unlocks using remote or the intirior lock.then yes would suspect barel.try lubricating with oil and jently working the lock with the key it may free off then inject greass into the lock.but if not the above then it could be the spring on the latch ass has broken,this jams the mechanism.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.