Can I be charged a restocking fee for something I have not received and for work that hadnt started

I had a consultation with a company called sun-tech its a solar panel company. They gave me a briefing on how it works I was told there was no obligation but I'd have to sign a worksheet agreement to have someone come asses my home to see if it could even be put up. They also wanted to check with a bank to see if I qualified for a loan which I did then I let them know to keep it on hold until I came to a decision. that was a month ago and a week ago I received a call from them threatening that if I didnt put the panels up I would be charged a restocking fee of $8,000! and if I didnt pay the $8,000 they would put a lean on my house and take me to court. They never did any work or brought any materials here and I didnt give them permission to do so. can they do this?