I've been trying to cancel the insurance

In October I bought a new a car and did a quotation with MiWay Insurance as I was their existing client. I then went for another cheaper insurance and requested that they cancel on their side. End of October they deducted my money. I phoned them to cancel and reversed the payment with my bank. Now they deducted my money again. I phoned the call centre and the lady told me she doesn't have authority to cancel. she transferred me to another line but there was no answer.