Your rights are determined by the terms of your Collective Agreement. Whatever your complaint is, it is very important that your union file a grievance immediately, or your rights may be lost. If your union is not representing you in good faith, you have a right to file a complaint before either the Canada Labour Relations Board if you are federally regulated or the Ontario Labour Relations Board, if you are not federally regulated. You may require legal assistance.

If you are not interested in reinstatement, and only want a monetary severance payment, then your rights are defined by legislation in the Province of Ontario, if you are employed in Ontario, and are not federally regulated.  If you are federally regulated, and are not seeking reinstatement, your rights are governed by the Canada Labour Code.  Sometimes you may have more generous rights to a severance payment than what is set out in provincial or federal legislation, because of specific provisions in your Collective Agreement.  You should be sure to review these provisions to see if your Collective Agreement provides for special severance payment rights.

To understand Federally Regulated Industries, read more.
To understand Legislation in the Province of Ontario, read more.