Sick of my job

So I've been working at this Asian takeaway shop since march. Firstly it's a cash in hand job, meaning I don't pay taxes, very illegal where I am from. They pay me $12 an hour, which I know most of you are from America and that's good. But where I'm from my minimum wage that they legally have to pay me is $15-$16 an hour.

I started out with one shift a week from 5pm-8-9pm at the latest. I never had a set finish time. If it was busy I was there until 9. If it was not busy I'd finish 8-8:30. I slowly after a month went to two shifts. Then three. Then they cut me down to one shift. Giving this other girl who works a full time job on top of this job six shifts a week. While me and the rest of the girls who work there get two or one a week.

So I was meant to work tomorrow for one shift this week. My boss messages me at 10:30 pm that she's giving my shift, which has been in place for a week now, to a girl who's come back from holiday. Who not only works with me but has another job too.

My partner and I have different work schedules, more so he's full time and the days he's free I'm working. So we finally found a day to go down to his family beach house and my boss asks me to work that day! I told her I can't, because I am busy during the day doing a course in the city and after that I'm going straight to the beach house. Wouldn't even have time to go from my course to work anyway. Which I told her last week I had.

I have another job in line that I start in a few weeks. But I need to buy a whole new wardrobe for it since it's a professional job that has no set uniform. I can't wear just casual and I've never had a job like this before. So I don't own any clothes for it.

I get some government assistance but I live at home and I get none of it. Since my mum makes me pay rent. And I only earn on a good week now $50. Which has to go on petrol, rego for my car, my phone bill. So I'm not left with much to buy nice fancy clothes for this job. That I desperately need.