******* debit orders (6 in the past month)

Why is nedbank allowing these ******* debit orders to be processed onto my account? Already I have had 6 x debit orders deducted from my account in the past 4 weeks. Each debit order carries a R5 dispute fee! This is downright unfair! I have disputed all of them but only 1 x debit order was returned into my account, the rest have either been ignored or closee without refunding, THIS IS COMPLETELY UNNACCEPTABLE!