I have asked for the last 2 days for someone to assist as I am busy changing my bank details, up to now no one bother to help me and my debit order is due on the 25th

I have asked for the last 2 days for someone to assist as I am busy changing my bank details, up to now no one bother to help me and my debit order is due on the 25th. No where on the app does it allow you to change banking details nor does anyone reply on my emails either.