Lack of Service

I'm so sick and tired of getting my account debited on a wrong date I made several calls to get the right due date corrected and to my surprise you guys tried debiting my account again on a wrong date and now that there are no funds whos going to be liable for the bank charges this service is so poor its actually worrying to think how will I be treated in case of emergency if they cannot correct a simple thing like a debit order date