Can’t cancel contract!

They continue to charge me when I cancelled my contract. They automatically renewed my contract without my consent which is one thing. When I contacted them to cancel my contract they said my last debit order would go off on the 1st December. I was then debited again today? Furthermore when I contacted them this morning they said it was my fault for not calling back to check it had been cancelled, even though I received sms confirmation that it had been. I explained my situation, was told that the call had been recorded and was assured that as of January I would be on 'pay-as-you-go‘.