When you can cancel
Cancel before the next billing date and the plan runs until that date.
A paid plan can be cancelled before the next billing date. Access continues until that date. The free trial does not require a card, so there is nothing to refund from a trial that was never charged.
What is refunded
A charge already taken for the current period stays, unless it should not have been taken.
Charges already collected for the current month or year are not refunded, except where a payment was taken in error or the service was unavailable for the full period. A renewal you cancel before it is billed is not charged.
How to ask
One email, with the payment reference, is enough to open the request.
Write to support@billnest.example with the transaction ID, the account email, and the reason. Refunds that are approved go back to the original payment method. Keep the reply until the amount shows on that method.