Debit Order cancellation

<p>I have been getting rude calls from MBD regarding my woolworths account. I was under the impression that I am paying my account every month as it's a debit order. Woolworths decided to cancel the debit order without letting me know and now I have rude people calling me regarding my account. I tried calling on Thursday to ask who authorised the debit order cancellation and I was on hold for more than 5 minutes. I am not sure how to go about this. </p>