so it wont open using the release button on the remote?
1st check the wires in the gaitor to the top left with the hatch open these power the rear door switch.
i too had a similar problem and stripped everything and it turned out the wires in the gaitor had snapped,wish i had checked this 1st as it took me an age to remove all the trim.
you wouldnt think that the smax/galaxy mk3s would suffer the same !Removed! problem that the galaxy mk1 and 2s suffer from but IT DOES.