Unauthorsied debit order

On Air TV sourced our banking details from their archives (we had cancelled all dealing with them a few months ago) and out of the blue began charging us R79.00 per month for a DSTV magazine which we do not want and have never received. When we called their customer care department, their representative became rude and petulant, insisting that we authorised the debit order which we clearly did not. Only when threatened with legal action did the "customer care" person agree to cancel the debit order.