Refuse to payback *******ly debited funds from my account

I took a short term policy beginning of November 2018. On the 9th November 2018 I contacted IWYZE to cancel the policy. On the 26th November they still debited my account for the cancelled policy. I immediately contactedvthe company to get the funds reversed. That did not happen.I this time went to a old mutual shop in Somerset where I was allowed to make a telephoncall to the office, they apologize d for the error and told me the funds will be deposited in my account within 5-7 days. Its now the last weekend in 2018 and no sign that they will deposit the funds in the near future or if ever.