Finchoice Harrasment

I took a 24 months loan and in April 2024 was a final instalment which was deducted by them. Because the instalment was more they had to refund the balance which they did. They sent me a paid up letter and end of May there was a debit order deducted on my account which I reversed and phone calls keep pouring requesting that I pay the arrears. I wrote emails and called but even today this matter has not been resolved. the amount outstanding is the insurance that they usually make to cover lost on debt, so now there is no debt what is the insurance for and it is generating interest and service fees. Last month I gave them the opportunity to rob me the amount that they say I am owing which they deducted and gave me the refund again. It started again that my account in arrears with the amount they refunded. Please advice for the way forward in order to close this account once and for all.