REPORT THEM
Do not use - they are a Rogue Trader and will cause problems in order to fix them at higher costs. No chance of getting any decent Customer Service or Refunds.
If anyone else has this misfortune, do what Salim and I have done and report to Gas Safe, Citizens Advice and Trading Standards. I'm looking into taking this further through the courts.
You are also able to report the company to The Insolvency Service and Action Fraud.
Help shut this company down!