I work for a canadian bank, they say i have breached a customers privacy. they treated to fire me what do i do? they also say i can not seek legal advice.

I am surprised that the Bank would advise you not to seek legal advice.  If you did use your position at the Bank to access information about a bank client for the benefit of your daughter, then, subject to any further information you may have, it seems a breach of the usual obligation of confidentiality you owe your employer, a breach of the bank's obligation to maintain the privacy of personal information that the bank keeps on its clients, and a conflict of interest on your part.  You should seek legal advice and have someone review the document that the bank is asking you to sign in order to keep your job.