Sadly this has to be one of the worst companies I have had the misfortune to deal with!
After spending nearly £3000 on 2 heating/cooling units we were supplied 2 cooling only units. Not being expert in this field we didnt notice the change of reference number that they made & hence we installed the units only to later discover that they provided no heat.
After over 4 months of e-mails & phone calls to get lines of communication open in an attempt reach an amicable solution (we were even willing to pay half the cost of the correct units) they did finally start talking with us but their solution was to expect us to pay another £2500 to cover their cost of the replacement units!
All we can suggest is avoid the company at all cost, sadly we had to spend £3k to learn this lesson.