betwisting betaling

Sir, Mrs; I did the online iq test. ASt the end of the test i was told that in order to get the result I had to chose to sign in and make a paiement of 19,5 €. I DID NOT SIGN IN and subseqsuentely never got the result of the test. But, on my last VISA account message I discovered a paiement done of the 19,5 € and a planned paiement for the next month. I woukd like you to 1. Stop these payments 2. Give me some prove of how you informed me of an agrement to pay.