FNB doesn't allow debit order reversal via phone, only app, and there is no option

FNB Forces you to use their app to dispute and reverse debit orders, then, the option isn't available for all debit orders. Prime example, I have cancelled my liffe insurance with old mutual. Yet, they still debited me. I can't dispute or reverse it. This is absolute BULL. The option should be available for every debit order, including their own.