2006 Vauxhall Zafira central locking working intermittently also unable to use key to lock doors

have you checked your ignition barrel? i had a similar problem on my car the key would release and come out but wouldnt lock on the key a jiggle on the key usually worked when taking the key out feel for a click as the barrel disengages and a bit of wd40 in the barrel. also check the wiring on the passenger side rear door i work part time in a garage and i have worked on a few zafiras the wiring inside the rubber gaiter has a habit of breaking try there hope this helps