Testora Won't Cancel Subscription

For the last nine months, Testora has been repeatedly charging me 49.99 per month without processing my cancellation request. This has resulted in a total of 449.91 being taken from my account for a service I no longer wish to use. I have contacted Testora customer support several times about this issue. Each time, they asked me to provide verification of ownership of my payment details, which I duly sent. After sending the requested verification, they stopped responding. I have repeated this process three times, but my subscription has still not been cancelled and the charges have continued. I am requesting that Testora immediately cancels my subscription and confirms that no further payments will be taken from my account.