How can I fix my UPVc door lock strip/central gear box?

Recently my door got jammed & the key function stopped working. A local locksmith managed to open the door and said the lock mechanisn had broken and which he removed from the strip. We are managing with the multipoint locking system which means always opening/closing by use of key even from indoors. He can't find the matching strip to replace this one.
My strip is Fullex SL 16. this was installed about five-six years ago. What can be done?
Thanks for all the help.