Hello i was scammed off FB Market Place with shed build. (el cajon)

Hello i am disabled vet. that was scammed off FB Market Place with shed build. The shed looks good from a distance but there are openings where spiders and insects can make a home and the door is wrong size they rigged in the opening but the thing i am really concerned about is the roof i could not see because they finished up at 10pm the shingles are not the same color and they did not put the roof paper down under the shingles and they deleted all info. so cant contact them. I am seeking someone to help me out with this issue i am stressed out about this i am sure it will leak if it rains so i would like to get it fixed before the rain comes. Thank you. I am seeking someone to help seal some areas and details any help i would appreciate if you know about wood working that would help the best way to fix issues thanks again.