I signed a contract to install a type of skylight (solar) with a contractor. On the day of installation, I was told that the intended skylight would not fit and they then switched to the skylight (fixed) that they had available in the warehouse. The contractor did not rewrite the contract or confirmed the price of new installation with me during installation. I asked for new quote but I was told they will work it out later. I was provided a final bill a week later for the lower grade skylight with a huge price tag. The price was way above the market price I gathered from various sources. I refused to pay the amount billed. I lodged a formal dispute wit them but no responses. Few weeks later I was sent an Intent to file a Lien letter. Do I have a good legal ground to take them to court?