Can employment agencies give you a job.then cancel and not pay you?

generally not. but depends on the situation though.

Not if you work

the job can be cancelled at any time but legally you must be paid for any hours you have worked.

no

They can terminate your contract, but any wages owed MUST be paid. Withholding wages is a criminal offence.

You are always entitled to be paid for work you completed. That is the law.

if you show up to work they are force by law to pay you 3 hours in Canada and 4 hours in the US. If they cancel before you leave for work than they don't owe you a thing. If they call you and you are on your way to work they are obligated to cover your transportation expenses. Keep in mind that the amount of time that it takes for you to leave your house and get to work is what is considered so don't think not picking up your phone will give you enough of a reason to say you were on your way or had to stop at the store and then headed to work, unless you can prove it don't lie....GOOD LUCK.....

No hard and fast rules here.

Depends on the individual agency,their contract with you and their deal with the client.

Sometimes the agent will pay you 8 hours as a gesture of goodwill if you have a good relationship.If the client cancels at the last moment then usually they will pay the agent a fee of which he ,hopefully will pass on to you.

not if you work already

Yes, if you are not able to work well accord to the agreement or you commit severe mistake that damage the establishment, your job could be terminated. How ever you should be paid according to the law.

Do you have any contract with them? They must pay your for time that you worked. Contact your state's Office/Department of Labor and Wages... I was in a similar situation. I called that office and they called the employer and explained the law to them. I ended up getting paid on time.

This should be covered in your contract with the agency.
They are entitled to make their own policy on this.