BAD SERVICE FROM LIQUID CAPITAL

We bought a 2015 Ford Ranger in 2017 this included a Service Plan ( Liquid Capital) .The Plan term was 36 months or 45000 km.The bakkie has very low kilometres.It was serviced in March/April which was covered by the service plan .We then took it in for a service in October 12 th 2018 and Liquid Capital has refused to pay for the service.They are now in the process ,since the 12 th October in getting a quote as their Call centre staff has advised us that the dealer undercharged us .Surely this is not our fault at all???