FNB Poor Service

Since April I have tried to stop a debit order from a Medical aid scheme of which I am no longer a member. It is now July and the issue is still not resolved. I have contacted the call center, my so called Private Banker as well as the online banking app. There are no options on the app to dispute or stop debit orders. I keep being referred to the COVID-19 option to apply for debt relief but the problem is I DO NOT NEED DEBT RELIEF! I need to stop certain debit orders from a company taking money out of my account and it seems I am powerless to stop it!