i urgently needed to stop a debit order

I called the call centre and requested that the agent please call me back. she literally said no she cannot and did not even give me another way for me to speak to them. I did not have enough airtime to stay on the line. another thing I am not able to even use my online banking. it always says my password is incorrect and I cannot change it.. there's always system issues with fnb. I am so unhappy with their service. I am changing my bank immediately.