MyIQ Subscription Charged Me Over $100 Without Proper Cancellation

I have a subscription issue with myiq.com that has been ongoing for several months. Despite attempting to cancel, my account has continued to be charged $29.99 per month via my bank MasterCard, and the total amount taken has now exceeded $100. I most recently noticed yet another $29.99 charge today. I previously contacted myiq.com customer support about these charges, and I was told that the issue was handled and that my refund was on the way. However, no proper resolution or refund has been received so far, and the charges have continued, which is very frustrating. I am requesting an immediate and permanent cancellation of this subscription, a full refund of all amounts that have been charged over these months (over $100 in total), and clear written confirmation that no further charges will be made to my card.