Revolution Roofing

I'm convinced I was misled. The original quote was low at $4,100, a thousand lower than others. But once all the shingles were removed I was informed that 60% of the plywood needed to be replaced and the final cost was $15,820. I'm a senior and I am sceptical that the final cost was appropriate or warranted. In addition I was not provided with a contract until all the shingles were removed and I had a house with nothing on the roof and with no option but to agree. As well, the price quoted for the plywood was highly inflated and I saw no evidence that 60% of the plywood was replaced. What I saw thrown off the roof was less than 25% or possibly only 10%.