Banking

I and my partner have been doing business for 10 years. Suddenly my partner went to wells fargo bank where we have joint account, took my name off from bank account. I went to branch office where we opened our account 10 years ago, bank manager told me nothing she can do except my partner come bank and sign me in the account. I am helpless. I do not have any access to business account. My partner refused to do so and bank is refusing to help me. Prior to this action taken by my partner withdrawing my name from account bank never notified me about this action.