I used the "AI" chatbot the last time I went through support — user error, paid full price for a book after forgetting to apply the coupon code.
Anyways, I asked the chatbot if I could refund the book and purchase it a second time to apply the coupon code. It then told me there was no method for refunding the book and then repurchasing to apply the coupon code. Then it told me to refund the book and repurchase it to apply the coupon code.
Thankfully, it worked.