roofer scam

I hired a roofer to put on my roof and he gave me a price without going up on the roof. He measured the house and gave me a price to re-roof the house. I found out that he had only put on part of the roof and now I have a leak in the part that he did not replace. A slop of 2.1 by 12 with rooled roofing and now the roofer I’m getting a price from to finish the roof said that the first roofer used a pro-armor underlayment and should by code have used a peel and stick. Is this correct?

Who cares, it leaked. Did the company have a permit? Contact your local building officials about requirements and your lawyer if needed. Best of luck.

Have no idea. What part of the world, specifically, are you located in? Regulations are different everywhere.