Petition a terrible co-op eval

My co-op eval shocked me. I got really bad, like really bad. I assure you it is bad. (Mar*****) I can't even type it without feeling shit.

• My mentor was on a break, so the manager decided to do my eval.

• They said that I was late for work or would log off early, mind you this is a remote job. To do the work I needed my laptop to do this task within the given time frame and this caused me to show offline on my work laptop and they deemed this as me ditching work. When I had said that I was doing work on another device because the equipment they gave didn't work.

• At my midterm in early February, my mentor said I was doing "good," but not great, and told me I needed to improve. I tried to get them to help me figure out a plan for what to work on and showed them the Waterloo rating, but they never really responded, even though I asked a few times.

• Throughout the term, we had some touchpoints, but my mentor never mentioned any of the big issues that the manager brought up in my final eval.

• I was working weekends and even doing unpaid overtime trying to do well, and still, my eval was crap.

• Another person involved in the eval tried to say good things about me, but it didn’t seem to make much difference.

• I’m not sure what to do next, given all this mess with the eval and the lack of feedback from my mentor.

How does a petition work and is CECA even worth contacting? I feel like it's gonna be a he-said-she-said battle.

Am I screwed for co op? My other ratings are really good but most recent one horrible.