Product: Credit card or prepaid card

I have an Chase Amazon Prime ( CAP ) credit card that I use to make all my purchases from Amazon because I earn rewards on all of those purchases. Chase and Amazon allow consumers to make certain large purchases via an " equal pay promo '' where the purchase can be paid in equal monthly installments over a predetermined period of time, such as 18 months, without incurring any interest. On XX/XX/XXXX, I purchased a new cell phone via Amazon with my CAP credit card for {$920.00} using the equal pay promotion and was scheduled to pay {$51.00} each month for 18 months with the first payment due XX/XX/XXXX and the last payment due XX/XX/XXXX. On my credit card statement, there are two balances. One for the equal pay promo balance which not subject to interest until after the equal pay promo period ends and one for all my other purchases which is subject to interest if not paid by the due date specified on the monthly credit card statement referred to as the " interest saving balance. '' Since XX/XX/XXXX, I have made many unrelated purchases via Amazon on my CAP credit card some of which I had to return for a refund. The original charge for the for those items was applied to my interest saving balance. However, {$280.00} of those refunds of were applied to my equal pay promo balance even though they are totally unrelated to the equal pay promo balance. As a result, I had {$280.00} in new purchases subject to interest if not paid by the monthly statement due date because Chase applied the refunds to a different balance than the original charge, Although I had planned on paying {$51.00} over 18 months in order to avoid paying any interest, I now had to pay {$280.00} over the last several months to avoid paying interest simply because I made a purchase, returned it, and received a refund which was all wholly unrelated to the equal pay promo. I called Chase and asked that they apply those refunds to my interest saving balance where the original charge was applied. A supervisor at Chase informed me it is their policy is to allocate payments and refunds not appearing on a previous statement to the balance with the lowest APR and that there is nothing I can do to stop that from happening and nothing that Chase can do to fix my balance with respect to those transactions. She explained that moving forward my only options are to not use the credit card for the next 18 months or somehow time any returns so that the refund occurs after the charge has appeared on a prior statement. As a result, I am stuck with paying an additional {$280.00} much earlier than I planned or face incurring interest on that amount. This seems like something that was not well thought out at best or predatory at worst. Either way, it is something that Chase is refusing to do anything about. Finally, the supervisor alleges there is something in the card holder agreement, which has to be mailed to me, about this. I would have accepted that well before I ever heard of an " equal pay promo. '' There was not anything I could find on Chase 's website or Amazon 's website addressing this situation. It certainly was not apparent or prominent if there is. I would imagine this has the potential to leave a lot of consumers in a precarious situation, especially if they happen to make a big purchase and return it. Part of the allure of using Amazon is the ease in which things can be returned. Therefore, the CAP card in particular seems well positioned to exploit consumers.