If your electrician changed the tails then the polarity problem would appear to be entirely his fault, of which should never have been left at that. Even as a temporary solution.
It would be good to see the final certificate once provided, along with a few pics. Make sure you also get a building control notification "building regulations certificate of compliance"
It would be good to see the final certificate once provided, along with a few pics. Make sure you also get a building control notification "building regulations certificate of compliance"