You can cancel your paid plan at any time by following these steps.
Sign In to your Account and go to the Pricing page.
Click [Downgrade] button under the Basic plan box.
Click [Change Now] button to confirm the cancellation.
or
Sign In to your Account and go to the Billing page.
Click [Cancel plan] in the Subscription box.
Agree to the terms of service in the modal and confirm the cancellation.
You'll be able to keep your paid plan for the remaining period until the next billing date.