How to get Ferrolli engineers to make a service call?

I have a Moderna 80e 2 1/2 years old that has been causing problems over last 3 months. Local corgi man has given up trying to sort it out so I called in Ferrolli engineer and paid £190+vat up front. They took 4 days to get here and because there were double yellow lines outside house refused to do job because he could not park, even though there was parking within 30Metres up or down the road. So don't buy a Ferrolli boiler if you live with double yellow lines outside your house as Ferrolli will not touch it.