I Need Testora IQ to Cancel Unauthorized Subscription Immediately

A week ago I registered with Testora IQ for a free IQ test. At no point was it clear to me that this would result in a paid subscription or binding contract. Today I suddenly received a contract confirmation from Testora IQ, even though I did not knowingly agree to such a subscription. The contract is linked to my email address vanessa.leyendeck****@gmail.com. I already tried to contact Testora IQ customer service to cancel this contract, but my attempt did not work and I was unable to resolve the issue. I hereby state that I do not accept this contract and request that Testora IQ cancel the contract immediately and delete any associated subscription. I expect written confirmation that the contract has been cancelled and that no costs will arise for me from this registration.