Broken trust

I had a clientelle legal policy and then I had to cancell due to unaffordability. I wrote them and email followed by phone call to cancell the policy in February/March. To my surprise they were still deducting their monthly premiums even though I had already canceled the policy, I then followed up by phoning clientelle to ask them why they were still deducting their premiums because I had already canceled the policy. They then said I must do it on my side as it is not their responsibility. Clientelle still deducted their premiums for the month of April/may /June. When I try to reverse it it doesn't allow me to and the bank can only stop the debit order. I would like clientelle to take responsibility for the money they took from my account and refund me my money back immediately, as from the bank side they say there is nothing they can do its up to clientele to refund me my money. So clientelle I want my money back