Terrible customer service

Dear FNB, Please explain to me how my debit order date got moved to a date that I definitely never agreed to, without my consent. I've tried to get this fixed through your Secure Chat feature in the app, but this keeps kicking me out every time my phone's screen goes off, resulting in a new chat starting and having to re-explain everything. I've asked whether an agent can phone me to sort this out, but I was just told that I could phone a certain number.