I love my job but I'm having a little issue with work-life balance and boundaries with my boss. I'm the only casual worker in a squad full of permanent part-time workers, so I have a couple scheduled days and cover sick days or other times I'm needed.
Recently, our workplace has been so overloaded that most days, the employees are going into overtime, staying an hour or two late every night. Manager has realised its cheaper to bring me on as an extra for half a day rather than pay 3 people overtime for however long they would have to stay back afterwards.
Here's the part where I'm feeling a little disrespected. I am being asked to come in, without fail, every single day, and refusing shifts as a casual always feels like the guillotine inches ever closer, even if everyone at the workplace is rather nice. I've made it clear to my manager that I would like a little more notice when possible and she's told me she'd try her best, but it still continues, despite how predictable it seems to be since I'm being asked, as I said, literally every day (weekends included). I had time off booked over three weeks ago to go over 6 days, and I ended up working for 2 of them (I made it clear the other 4 I wouldn't be in if everyone else on the team suddenly dropped dead at once). The worst part is, when I get there, it seems like the place isn't even all that busy. The work for the day is bottlenecked at certain parts and I struggle to find ways to make the day go faster regardless, and the other workers don't seem overly stressed either.
I don't think they can hire someone new because they have plans to expand the facility to make the bottlenecking of tasks not quite as bad, so this shouldn't continue forever. However, it most likely will still be a matter of months and I can't keep it up that long. I seriously do love this job though, its just as a person I couldn't take this many days with this little notice at any job. I just need some ideas of what to say to my manager to make myself firm and heard that I need some days that I know I will definitely have off and more time noticed when asked to come in without sounding too aggressive since I seriously do enjoy and need this job and would prefer not to make any enemies.
This is in Australia btw for any advice that might go in the legal direction.