No care inability to resolve an issue

I cancelled my data contract well in advance, to ensure no further costs. I then received an email with an invoice. I called in to ensure that the debit order would not be taken out of my account. But of course, this was taken. Does anyone think that I would just accept it? I will be reporting this matter to the ombudsman as trying to get Vodacom to sort out its mess is non-existent.