It would be used to pay for your next payments.But you can contact the moderators to try to get the refund if necessary.I'm not sure if they will refund the payment.Best of luck!
To change your plan in advance (like before the next renewal date),you can just simply do it on My Account page.However, you should know that you will not be reimbursed for the remaining period for the current plan and you may have other extra charge...
