My job refuses to make me permanent and keeps switching my role

I started working for this HHA company in May 2018 as a temp in a hot and dusty file room. It has no working vents, no sprinklers. Just a camera and wall to wall file cabinets. Within the first two weeks of working there I became sick with bronchitis and was out 4 days. I had a note. Afterwards it was repeat sinus infectious, colds, the whole nine. I didn't call out for them all, just a few. Around 2 months in when I was attempting to call out I sent an email to the manager instead of speaking to someone as no one answered. Even though there is no clear rule about this on our rulebook I was written up for this. I took it in stride. After my three months probation was up I asked about being made permanent. I was told there was no need for the position to be permanent and I am still temp. So I continued working in hopes of a promotion that I was told was coming. In October said promotion was here. I became a HR Assistant. But the position was also temp with a chance of going permanent. The position offered me a few hundred dollars more a year so I went ahead. Ironically when I left the file room that position became permanent. They hired someone and made them permanent. My HR assistant position was temp. I shrugged it off and told myself there is still a chance. Now while working I got tendonitis in my middle finger from the door closing on a joint. Once again I had to call out but they asked for a note despite that being against sick time laws. I provided one and I showed them the injury. Monday comes along and I came in late due to my appointment running over and I spoke to the HR assistant to my manager and I spoke to the VP who runs my department. I got written up on Monday for speaking to the managers assistant when previously I was written up for speaking to no one. Once again I signed it and shoved it from my mind. I looked through the rulebook and once again it isn't a clear rule. Once again I get sick but this time it was laryngitis. Even though my note said to stay home I was basically threatened because I was absent a lot (all excused with notes) I was in danger of losing my job. So I came in. We had a fire drill and I wasn't allowed to get my coat. I had to stand outside for 20 minutes with no coat and it was just above freezing. That combined with the laryngitis and I got pneumonia. I was actually told to leave as my cough was distracting the others. On top of the pneumonia my heart had expanded in the left ventricle. This time because my note said not to come in until Wednesday they sent me home as it was a serious issue. I recovered. Now I still keep getting sick because where we work now only half the vents work. It's also very up and down in temperature. However I have called out less and I try to work through it. Today I get called into my VPs office and I'm told the position is no longer needed as they closed a lot of facilities. I was given the option of today being my last day or the fileroom. I took the fileroom as I still need steady employment but not before asking about positions I know were vacant. I was told one position was filled and the other I wasn't qualified for. I can only move sideways and not up. While sitting at my desk gathering my personal items as I am rejoining the file room and there are now 6 people including myself in a small room with no vents (I am certain that's a fire hazard as we also have no sprinklers) I overheard the recruiter calling people who posted their resume to the data entry position I was told was filled. Upon asking her she said it wasnt filled yet at the salary isn't desirable. At this point I feel as if the company doesn't want me as an employee and is basically bouncing me where they see fit. Each time my role has changed I have to restart my 3 month probationary period. Do I have a case?