Documentation requested - no assistance given

I requested a copy of debit authorisation forms, where I gave permission/authority to Vodacom to debit my bank account, for Account I***. When my contract came up for renewal in 2012, I was given the option to pay via debit order or manually at the store. I opted for the paying manually option and at no point gave any authorisation on the renewal of my contract to debit my account. Having already requested this information from Vodacom and not receiving any assistance, I now request the same - a copy of any document/authorisation form where I granted permission for Vodacom to debit from my account, via this forum. A renewal of a contract does not give Vodacom the right to then use previous bank details to debit my account without my consent. Bear in mind again, payment method chosen was Manual and NOT debit order. Kind regards Marko