Am I screwing myself for leaving my community service slightly early?

I'm doing court ordered community service at goodwill. I filled our a document where I put down what days I can work and how many hours per day. I put down 3 hrs. Well, my supervisor tries to keep track of how long I've been there and he tells me when my 3 hrs are up. Sometimes it's a few minutes before the 3 hr mark, and one time it was 10 minutes before. I told my supervisor that, and he was like "they're not gonna care" so I just left. Well I read a paper I got from the Lieutenant who set up my community service, and it says that my hours won't count if I'm not staying my full shift which would be 3 hrs. It also said that I could be terminated from the program if have bad work habits, and im pretty sure leaving early is a bad work habit. I called my mom about this. She said that it's not a big deal and to just stay the full 3 hrs for now on. I was trying to call our boss, but she's not picking up. I'm just freaking out, because the rules are pretty straight forward and I'm just fucking it up.

Am I screwing myself for leaving my community service slightly early?
Post Opinion