If you were promised several things (verbally)before you got hired at a company example: you would not have to work week-ends,pay etc. Then a new boss comes in and tells you ,that will not happen. You took the job because you were promised that you would not be working week-ends(because you can't) Do you have just cause to quit are you protected by any laws etc?

Normally no unless you have a written job contract, and even then it may depend. Companies are allowed to change your pay, your work days and your working hours, even the job you do if they desire.

First of all, verbal promises don't mean a thing, anyone can make verbal promises.

I don't know where you are located but here in Ontario if you are terminated then your unemployment insurance kicks in within a couple of weeks, if you leave voluntarily then you have to wait six or eight weeks. Most people just go out and start looking again rather then go on the dole.

No your reason isn't just cause.