Vodacom didn't switch debit order details now threating to stop services

I recently changed Banks and phoned Vodacom a month back to update the banking details. When month-end came they tried to debit my old account. I then called again to confirm new banking details, they then updated the details(I hope). I asked Okay so will you debit the account now or what? they said it would be debited twice on the next debit order run. For the past week I have received smses and phone calls stating I need to make payments or else my services/ account will be stopped. I have been with Vodacom for over 10 years and have never missed a payment. Vodacom, you originally told me it would be debited twice, can you please stick to your word? you can go listen to the voice recording, I am not going to make a manual payment now I'm sorry. If you debited the account like I orginally asked you we wouldnt have this issue in the first place.