Amazon Sent and Charged Me for Resin I Never Ordered

I am writing regarding an Amazon order with the number 112-6799593-3955451, which was delivered to me today in Silver Spring, Maryland, USA. The package contained a Lets Resin 2 gallon resin, but I did not place this order. Some time ago I had a subscription for resin through Amazon, but I canceled that subscription and then closed my old Amazon account. Later, I opened a new Amazon account under a different email address. Despite this, I have now received this Lets Resin 2 gallon resin order and I see that I have been charged for it, even though I did not order it. I tried to contact Amazon customer service about this issue, but they told me they could not find this order number in their system, so I could not get any help or a clear solution. I request that Amazon provide clear instructions and a return label so that I can send this Lets Resin 2 gallon resin back at no cost to me. I also request a full refund for the amount charged for this unordered product and a check of my account and subscriptions so that no further unwanted resin orders are sent or charged in the future.