rusted panels after only 4 years

Hello Everyone, Geographical Location: Amherst, MA Message: Our metallic copper pained metal roof was installed 4 years ago by what appeared to be a very knowledgeable and professional local contractor. Only 4 years later the panels along side the chimney are terribly corroded, 2 large rust spots primarily at the edges. The contractor claims its from creosote and said its entirely our fault for not burning the wood stove hot enough. After reading the warranty we find it's up to the contractor to send the company (Englert) photos and details about the metal roll itself in order for the company to send a rep. out to review the roof and damage and asses what caused it to occur so quickly. We know they had not replaced the flashing when they installed it, and if the flashing is lead, the warranty specifically states that roof repairs will not be covered. We also could not find a chimney sweep who had the right equipment and was willing to go up there and clean the cap, so of course there was a lot of creosote. Over the years we had contacted them several times asking for help finding a chimney sweep with metal roof experience; and even though they are local and in business for many years they said they could not help. We were so worried about voiding the warranty by having the wrong person go up there and scratch the panels, that the real culprit was staring us in the face the whole time, creosote and lead flashing ~YIKES!! Now we have to trust that the same people who failed to even inform us of these risks are going to handle procedures with the company correctly in order to validate whether or not it will be covered under warranty. Caveat emptor…how is an average person to know these things if the contractors they rely on fail to inform them of the potential problems that are right in front of their faces? Gee do I feel stupid. Any words of advice?