Boiler replaced - dual system - central heating ra...

Boiler replaced - dual system - central heating radiators and underfloor heating. As soon as I started to use, underfloor heating just not functioning. Despite having a warranty which stated Everwarm inspected my system prior to installation and replacement would be compatible and giving an installation warranty, they are now side stepping their responsibilities and saying they don't do underfloor heating.
This company must be getting millions from the Scottish Government under terms of warmer homes Scotland scheme yet blatantly renege on their installation warranty.