Digital Satellite Warranty Cover — unauthorised direct debit

This Company have taken monies from my account without my authorisation. Have had four phone calls from them suggesting my cover is running out and would I renew. My answer to all four calls was an emphatic NO, they have gone ahead with a Direct Debit, which I DID NOT agree to. I have cancelled the Direct Debit with my bank, they inform that I need to contact the said Company to cancel with them. I first had to obtain the phone number through Directory Enquiries, but no answer to my calls. Sincerely Donald Paffey