OP here. Just some additional clarification. I'm in Canada, so I could contact the provincial Ministry of Labour, but I don't think that they would be able to help much...well, I don't know actually because the owner treated this position as freelance with the promise of a salaried position after a few months.... yet another fib on his part. Sorry I didn't clarify that much, much earlier. I can call into the Ministry's hotline, but haven't thought it would make a difference. I will certainly try though to find out if I have any protection through them on Monday.
Additionally, I don't have a lot of paper proof. I feel like a complete idiot for not following one of the things I recommend to people which is to follow up conversations with a clarifying email i.e. "Just to review what we discussed today....". I have been kicking myself over for being trusting. I always assume people will do the right thing. Anyway, part of my anger at the owner is also anger at myself for not having done more to protect myself.
Anyway, DH will speak to a lawyer we know to ask if there is any point to sending a letter and I will call the Ministry on Monday to see if they can do anything. Honestly, I just don't get how people can behave like this.
Thanks again everyone!