Man Of Steel General Contracting

My 84 year old grandparents hired this guy to do a roof for them. I was unaware of his unprofessional behavior until the last day of the job when I stopped to check in on the progress. The main roof was already finished and only part of the porch roof remained. They said the contractor seemed professional at first. His quote was "$11,500-12000" including clean up and cleaning out the gutters of jobsite debris as a result of the tear off. He had a long list of references. My Grandparents hired him and when he came to the house to write up the agreement, he took back his original quote and gave them a re-worded contract that was missing some things. He also took back his list of references. Then he tried to get my Grandparents to "split" the price of a dumpster with him. They refused because he initially said he would remove all debris and clean up the site after the job. His work was slow at first. He consistently showed up mid-morning and usually appeared intoxicated. He staggered around a lot and tripped over things. He and two other workers would all disappear into the small jobsite trailer together for periods of time and afterwards his staggering would be much worse. One day he had extra crew members and one of them started screaming at Marshall about being so drunk and that he would be damned if he was going to let Marshall fall and drag one of them off the roof and kill them. The roof appeared ok from the ground. On the last day 10/21/2020, one worker showed up and finished the porch roof in the rain. I stopped to inspect the finished product and saw that the gutters are full of shingle pies and pieces of wood. The gutters are overflowing and broken away from the roof in places. The porch roof is sagging and the hip caps look like a snake, the caps missed covering many of the nails. The entire porch roof is spongy and you can see the shingles squish in when you walk on it. I called Marshall and he came and fixed the caps to cover the nail heads. And agreed to clean out the gutters. Marshall was visibly intoxicated as we all observed him working. I brought up the issue of the porch roof being spongy and it visibly sags when a person walks on it. Marshall insisted that the roof had been re-sheeted and was spongy because it was " a hundred years old". I countered with the fact that he was hired to fix the roof in the first place, to which he said he was only hired to tear it off, re-sheet it and reshingle it. Today 11/1/2020 there is standing water on the roof and water is leaking through the porch roof. There gutters on the house are over flowing or leaking with shingle pieces clogging them and sticking up out of the gutter in multiple places. I called Marshall today at 11:15 Am, it took two calls. The first call he picked up and utter something incoherent, I asked "is this Man of Steel general contracting?" He made some noises and hung up. I called back immediately he answered incoherently i asked the same question twice. And he said "yep". I informed Marshall who I was, where I was, that he was hired tonput a new roof on this address, and that the porch roof had standing water on it and is leaking water out of the soffits. He uttered "I'll have to go look at it one of these mornins". Now we are stuck with a $12,000 defective roof.