Immediate Cancellation Of Costext Subscription

I recently used Costext.com to purchase the sending of a single message. After completing this one-time purchase, I logged into the website and, in the transactions or account section, I saw that an active subscription had been created for my account without my consent or authorization. When I click on the “cancel subscription” option, the system does not allow me to cancel it and I am effectively blocked from terminating this unwanted subscription, even though no payment has been charged yet. My account on Costext.com is registered with the email address: bennyblanc***@libero.it. I never agreed to any recurring service, and I only intended to make a one-time purchase. I request the immediate cancellation of this subscription, written confirmation that the subscription has been terminated and will never be billed, and the deletion of my personal data related to this subscription from your systems. I kindly ask you to handle this urgently and confirm the actions taken in writing via email.