We had a conservatory built by a local company and were originaly hoping for a glass roof as pictures looked nicer. The salesman disuaded us because he said it would be heavy and too cold in the winter, too hot and glaring in the summer - better to go for polycarbonate which has a honeycomb construction and has excellent insulation. So we went ahead and were given a 10 year guarantee. We have had to regularly clean the roof as we live under trees, the leaves and debris from the trees fall onto the roof and gutters and make it look dirty inside and out. We recently noticed algae growing in the chambers of the honeycomb polycarbonate and we are unable to clear this out as the chambers are narrow - the roof panels need replacing. The guarantee is still in place but the company refuse to do anything as the manager says for the algae problem to be so bad we have not had the roof and gutters cleaned annually. In fact we've had to have it done more often than annually as it looks awful covered in tree debris. He also said this has occured because it was built under trees - a fact which infuriates me as we were advised by his salesman to go for this roof type when the trees were there for him to see, just as they are now. What can I do? Who can I complain to? I'd be very grateful for your help and advice.