To request a refund, contact the store where you purchased your item. Using their return policy, the store will advise if a return is possible. If a return is possible, then the store will advise how much the refunded amount will be. After your refund is processed, the refund amount will be applied to your original payment method within 3-10 business days and your balance will be updated.
If your refund is less than your total purchase balance, then it might not lower your next payment. Instead, you can expect fewer payments, a smaller final payment, or both.
If your refund is more than your purchase balance, then the difference is returned to your original payment method within 3-10 business days.
If your order is made with interest payments, then the paid interest isn't refunded. When you make payments, the funds are first applied to the accrued unpaid interest and then to the principal. Interest is the cost of borrowing, and isn't refundable.