How to get my wage from an unreasonable boss?

[caelin]

I was on duty on my last day of work, but my boss fired me on the spot.
She is not happy that I'm quitting and insist I must give her letter of resignation and a month notice.
I had told her I want to quit before Christmas but I stay because she said she need people to help her till Chinese New Year is over. Maybe she forget again, she is quite a forgetful person.
Two weeks has pass, she has not paid my wage for January(month of Cny).
She tries to threaten me with Malaysia labour law and has many times riled me nastily on the phone.
She did not give me any letter of offer or any service aggreement, everything were agreed by words from the mouth. I have the salary slips that do not contain any detail to prove she made it.
I'm working as a part time sales girl, unlike any of them I have to work 7 hours on normal days, full day(12 hrs) on weekends and one day off per week.
What should I do now?

[alleyne]

So why did you take the job if you were not given any service agreement?
A letter of resignation and a period of notice is common in all companies worldwide