My IQ Test Charged Me Repeatedly After a $1 Trial Without Consent

I recently took an online IQ test that was advertised as costing $1.00, which I believe was associated with Mensa or a related “My IQ” service. During this process, I did not at any point intentionally create an account with Mensa or any IQ-testing platform, nor did I knowingly authorize any recurring or additional charges. Despite this, an account appears to have been created without my consent, and I have now been charged twice via Venmo for $29.99 each, on or around May 15th and again on June 11th. One of the transactions on my Venmo account is listed under the transaction ID 4615281824868253236. I live in Fort Collins, Colorado, and I noticed these charges only after reviewing my statements. I have never agreed to a subscription or membership, and I was not clearly informed that further payments beyond the initial $1.00 would be taken. Due to these unauthorized charges, I have already contacted my bank, which has placed a stop on the latest account activity to prevent further withdrawals. However, this does not resolve the fact that an account appears to have been opened and used to bill me without my explicit and informed consent. I request a full refund of all unauthorized $29.99 charges that have been taken in connection with this IQ test, immediate and permanent closure of any account that may have been opened in my name or linked to my Venmo, and written or email confirmation once this has been completed. I also expect a clear explanation of how an account was opened and charges were initiated without my knowledge, and what measures will be taken to prevent this from happening again to me or other users.