If an employer wants to dismiss an employee for cause the employer is required to provide the employee with written warnings, unless the employee`s conduct is so extraordinary that immediate dismissal is warranted.
As this was not the case then you should consider a claim for wrongful dismissal and seek damages from your employer.
Generally the damages would be equal to what you would receive had you been dismissed without cause. If that had been the case you would have been entitled to receive "reasonable" notice or pay in lieu of notice.
Generally, in determining what is reasonable notice Courts look at several factors including the length of time you worked for the employer, your age, your position, the likelihood of finding new employment etc.
At the high end, if you were in a managerial position, the Court would likely order one month's notice or pay in lieu of notice for each year of employment. If you were not in a managerial position the Court would order somewhat less.
So your next step should be to consult with an employment lawyer as soon as you can.
You can contact the Law Society and use their Lawyer Referral Service. You will be given the name of a lawyer and can consult with the lawyer and the first half hour will be free.
The number is:
(###) ###-####(within the GTA)