During the pilot nothing is charged, so there is nothing to refund.
When there is a price: monthly plans can be cancelled at any time and stop at the end of the period paid for; a sitting pass can be refunded in full within 14 days of purchase if you have marked fewer than five written answers. After that, a partial refund for the unused months is at our discretion, and we lean towards yes. Write to help@marklinehq.com with the email you signed up with.
There is no financing and no balance owed if you stop. Stopping payment stops the service and the bill.