Unauthorized deductions off a bank account

This is a case where the wishes of a bank account holder are being ignored. I went into an agreement with this organization for membership. Due to covid, it became very hard for us to uphold this membership fees. So I canceled this membership as from 1 February 2021. This was okay, but out of the blue members fees were deducted off my wife's account during the month of May 2021. I sent another cancelation mail, but during June 2021 another deduction were made. So every time it is banking fees, for something we have supposed stopped.