Resist Unauthorized access to clients account by FNB

I would like South Africa and the world to know of the unprofessional conduct of FNB. The bank accessed my account and withdraws without my consent. After complaints through the consultants and a branch manager, the bank then Fnb refunds part of the money and apologies for the occurrence and promise to refund the remaining balance with immediate effect. Its been a week of empty promises . I have made more than 10 calls and trips the bank and received several apologies in the last week. This is not the first time FNB is doing this and then gives several apologies. Accessing a client's account without consent is ******* . I joined FNB after being convinced by family . I am planning to close my accounts and seek legal action.