FamRadar Subscription Cancellation and Unauthorized Charges

I made a payment of 39,99 € to FamRadar about four months ago because I wanted to monitor where my son was going. After this first payment I stopped using the service, but today I noticed that FamRadar has continued to withdraw money from my bank card without my knowledge or clear consent. I realized this problem today when I saw the FamRadar charges on my card. I never approved these ongoing withdrawals and I do not want any further money to be taken from my card. I request that my subscription or any paid plan linked to my card be cancelled immediately and that the amounts charged to me without my explicit approval after I stopped using the service be fully refunded to my bank card.