Bison Roofing & Solar

Paid for product/services never delivered and company refusing to return monies.
I asked for a refund for $4,738 for a work, on their recommendation, to add a pitch to a new flat roof that they were installing. Additional money was paid in full, but no pitch ever added. The owner, repeatedly insisted there was a pitch. I had both town and state inspectors inspect the roof, confirming that there is no such pitch, along with several other issues with the new roof itself. Bison was informed of the proof that they had not provided a pitch, but at that time changed to saying that because they had to use extra materials and labor to fix leaks, (on the flat roof they that installed at almost $40,000), they would not refund the monies for the separately contracted, billed and paid for project, ($4,738). Some background info is warranted
I first contacted Bison roofing to obtain a quote for the replacement of a flat roof on my 3 bedroom house. Once I had accepted a price I feel I was pressurised and misled into installing Solar Panels amongst other things. They then used aggressive sales techniques to get me to sign up to the work, now nearly $40,000, right there and then, and call to arrange this finance whilst still in my living room. I know it was foolish now, but the project went ahead without any real chance to reconsider the financing or work, and I am now led to understand that they should have told me there was a cooling off period, where I could reconsider. In fact once I had signed the contract it was taken away and I was not left with a copy. I did not receive a copy of the contract until after work had not only commenced but was supposedly completed, at which time my ceilings and home were in a mess. No conversation took place informing me I had a chance to reconsider, in fact quite the opposite, I feel I was strongly pressurized into an immediate decision.
No physical inspection of the existing roof was conducted as I was told that was no requirement to do so as they use satellite imaging to view the roof before providing me with the original quote, and the as such they were aware that I had AC unit and ducting on the roof. I was given the clear impression this was all part and parcel of replacing the roof. I of course did not expect the AC ducting to be replaced, but the roof to be refitted to accommodate that. After a couple of days their representatives, Andy, arrived at my house telling me that I needed to completely remove the ducting and that I would be better off to have multi-unit AC system fitted. I did not agree to that on his first attempt/visit but he persisted in calling and persuading me to consider this. They estimated this would be around $4,500 - $5,000 and of course knew somebody who could do this. It ended up costing nearly $10,000 and was in itself another complete mess. When workmen turned up to commence the work on the roof they would not start until the ducting was removed, despite the lack of time for me to get an accurate quote for the multi-unit AC, or fully understand the implications. Again, I had been led to believe that the additional pitch I had paid for was to allow the AC piping to be run through the roof space. I now have thick cables running along the top of the walls in two bedrooms due to no pitch space to run those. In addition to this they said they needed to add a further $4,738 to the original price for the roof in order to add such a pitch to it, facilitating space for the AC contractor having additional room to run vents, saying 3 additional cooling vents would be added to allow the removal of hot air, these were not added. Their written suggestion said that if I did not pay an additional amount for the pitch any warranty would be void, I would almost certainly have damage once water collected, and it would facilitate a new AC ducting system through the roofing space. Again, this was a written additional quote and contract suggested and provided by them.