Cancel My Testora Subscription Immediately

I have a serious problem with my Testora subscription. Although I have tried to cancel it today, the subscription is still active and I keep being charged against my will. The amounts taken are different each time, and these unwanted charges have been occurring since 6 June. After noticing this, I contacted Testora customer service and clearly explained that I am still being charged and cannot cancel the subscription. They only told me to wait 24 hours, but this is not an acceptable solution for me because the subscription continues and I am concerned that further payments may be taken. I request that my Testora subscription be cancelled immediately without any further delay so that no additional charges are made to my account.