Air conditioning controllers

Hi. Looking for help!!!.. please!

just bought a Samsung air conditioning unit on the understanding it cools to 16deg… Long story short the wall mounts do but the ducted units don’t, even though they should operate down to 16deg the controller firmware limits it to 18. Is there a way of forcing the unit to use the controller version used by the wall mounts through ST ?. Trying to avoid a tricky legal situation of asking it all to Be removed. Any help greatly appreciated.