Bank charges on re-submitted debit order cost 6 times the amount of the debit order

MWEB resubmitted a debit order on my account seven times, costing me R960 in bank charges. Surely if a debit order gets returned, there's a reason? I rep**** to the email I received, I sent a separate email as well, but apparently none of those were received. I have now had to change my bank details via phone. So basically, wasting my airtime to manage a simple task of changing bank details and still getting charged another R120 for a returned debit order. On a R119 per month account. So basically, Mweb and Nedbank have now caused me charges of over R1000 for a R240 account charge.