debit order date not updated since 2015

Prior my retirement i had asked OM to change my debit order date and have physically went to their office to have them effect this change. since 2015, what has been happening is that they deduct money on my account when i do not have sufficient funds, thus resulting me in incurring bank changes. I want you guys to fix this mess and re-imburse me all the monies deducted from your account, as i am suffering because of your incompetencies.