Refund on premuim

On the 26th of February I wrote a mial informing discovery insure that I give them 1 month notice to cancel my insurance due to financial difficulties and that I got cheaper insurance. 31 March another debit order went off and the morning of 1st April I made a complaint asking them to please return my money because I cancelled a month before. They called me back immediately trying to save me from leaving but I explained that this is only due to financial difficulties and would still like to part ways and that I need the refund to be made because the new insurance also debited, they said it is fine I must please allow them 5- 7 days for the refund to be made. I followed up on the 08 again and the response was to wait for feedback and allow then 5 - 10 days. This is unacceptable I explained numerous times this is due to financial difficulties but now I must suffer because of their incompetence. Really unacceptable