Cancelled Policy debit order went through now struggling to get my refund

My dad canceled his policy on the 17th of March but the debit order went through from my account on the 25th as I was the one paying the premiums all along, as I try to get my refund I’m being sent from pillar to post, this is just beyond disgusting because you’re messing with peoples livelihood. I just want my funds back into my account is that too much to ask for?