That is a new roof? Unfortunately if you did not get anything in writing your pretty much hosed. That roof has poor workmanship all over it.
Pic #1 It has a sloped roof jack, and the cap is screwed to the roof jack, if it is a exhaust flue, the cap is attached to the pipe not the jack, and the jack should have been straight not for a sloped roof and a rain collar installed.
Pic#2 Looks like the lap of a torch down? That they didn’t do right and slapped a little mastic on it to call it good.
Pic#3 They tied in to a step up area that dies to a mansard, the stepped up area should have been replaced at the same time, how hard would that have been? Again, slapping mastic to patch a new roof is not right.
Pic#4 Tie off in to another roof with divider wall there, this whole area is wrong, wrong wrong.
Was this a lay over?
Was this the cheapest person in town?
Relative did the work?
What made you chose this guy?
Not trying to be a prick but I see this every day, get stone walled out of jobs because hacks do things like this, and sadly a fair amount of home owners do not learn their lessons. Even if this guy charged $300 and I’m sure it was more, i would charge more to tear this off and do it right because of all the extra work he made me do. Anyone in their right mind would do that same.
So unless you got a good signed contract your out the money, you could try and go to small claims court but with out signed papers they probably won’t even hear your case. My just be a expensive lesson learned.
On the bright side you will have 50 people tell you that it can be fixed, those 50 people are only 1/2 correct, it can be fixed but it wont last long.