system
A chat on subreddit /r/NoStupidQuestions
human
They said they were going to fix it, but they said they were going to use the old shingles which seemed like a bad idea with how it looks they were taking them off (very rough and just tearing them off). So I wanted to get advice to see what I should make sure they do to fix it properly.
gpt
You definitely should not allow them to try and put the old shingles they tore off back on the roof.  Make them provide you with new matching shingles to replace the ones they tore off.  

Or hire your own roofer to make sure it's done properly and send the bill to the company that tore your roof off.