Non cancellation and refund of debit order

On 25 or 26 February 2016 I called the call center to cancel my insurance policy. The retention department was quick and fast. I was promised a refund within 30 days of my debit order for end of February.<br> <br> 26 March 2016 came around and instead of a refund, I received a notification of a debit order. This shocked me as I clearly cancelled my policy!<br> <br> After the long weekend, on 30 March, I called the call center to find out that my policy was never cancelled.<br> <br> I would like an explanation as to when I will be receiving my refund and why my policy was never cancelled.