I Need a Refund for Unauthorized Teste QI Subscription Charges

I am writing to report that I was charged for a weekly subscription to Teste QI that I never requested or authorized. On my card statement, two charges of US$14.99 each appeared, dated 29/05 and 05/06, even though I did not subscribe to any weekly plan or give prior authorization for these debits. When I noticed the situation, I immediately cancelled the subscription with Teste QI and blocked my card to prevent new unauthorized charges. Despite this, these two amounts have already been debited and I was not previously informed in a clear or explicit way that I would be charged. I request the full refund of the two charges, totalling approximately US$30, and I also ask for written confirmation that my subscription has been fully cancelled and that no further charges will be made to my card.