Why McAfee refused to refund me £85 for an unused subscription auto-renewal?

Please can I get refund money from McAfee that they took without any authorising, I have been in touch with my bank and they have advised the fraud office of your activity you must email me your response regarding this matter, you have charged me £85.00 for what I don’t even know it is on my bank statement charged from my debit card without my knowledge or authority and how did you obtain my card details as I never gave them to you I await your immediate response.