We feel very sorry that you want to leave us. If you've paid using PayPal, you can cancel the subscription in your PayPal account: https://www.paypal.com/us/selfhelp/article/how-do-i-cancel-a-subscription-faq577
Otherwise, please, contact our support: firstname.lastname@example.org
We would highly appreciate if you could specify the reason of cancellation since we are interested in improving our service. Thank you!