Struggling with a Debit order that was cancelled and keeps going off every month

*** 220626

Debit order cancelled in February 2022 via email. The unlimited still taking off debit orders every month for the amount of 275.00 I have Discovery Medical Aid so the hospital cash plan is no longer required.

I am struggling to stop this stupid debit order and the Banking App does not allow me to reverse, also a consultant was suppose to contact me and no one has! How can a person cancel a debit order for good? Must I close my FNB account????