Canceled Amazon Order Still Shipped, No Clear Way to Repay

I had canceled an order that I placed on Amazon. Despite the cancellation, the product was still shipped to me, and at the same time, the refund was processed. At this point, I have both the product in my possession and the refunded payment. Since I want to keep and use the product, I would like to pay for it, but I cannot find clear instructions anywhere on how to do so.

For the past two days, I have been trying to contact Amazon through the in-app messaging system. Although I received responses to my messages, the answers were not clear or properly guiding, and as a result, I still do not know what steps I should take. I also could not find a customer service phone number that I can call, so I am unable to speak directly with a representative.

I am requesting that Amazon provide clear and explicit guidance on how I can make the payment again for this order, clearly outline the steps I need to follow, and offer a more accessible customer service channel for customers to reach in situations like this.