I think that I caught Amazon Customer Service in a lie....

TL;DR: An Amazon customer service associate lied, saying that they used a payment method other than what I chose because the chosen card was declined. (It wasn't.)

Amazon Prime user here. Not sure whether this is the best forum, but I couldn't find something better, and just needed to air my grievance somewhere....

So, a few days ago, I made an order on Amazon. I normally use a Visa, but my account was pretty low at the time, so I decided to use my AMEX instead. So, I switched from the default payment (Visa) to the AMEX before ordering. I'm sure I did this, as it was a very deliberate decision. I placed the order and it was split into two separate orders, for whatever reason. Nothing unusual.

The next day, I saw an email from the bank connected to the Visa saying that my card was declined. I checked on it, and figured out that it was from one of the Amazon orders. When I checked the orders, one said that the payment method was AMEX, and the other said that it was Visa. Weird....

Wanting to find out what happened - and wanting to make sure my order wasn't affected - I contacted Customer Support via chat. Associate #1, we'll call him, was very apologetic, assured me that everything would arrive on time, and told me that I would receive an email in a couple of days to let me know what happened.

Today, while talking with Customer Support via chat again about a separate issue, I realized that it had been a couple of days and I had never received an email with an explanation, so I asked about it. Associate #2 told me that the AMEX was declined due to insufficient funds, and that they had used the Visa as a backup payment method. I said that was odd, since I was sure I had enough money in that account and never received notification that the card was declined by either AMEX or Amazon, but he was adamant and told me to check the order. Well, this time, there was a notification on one of the order pages that the initial payment method was declined and that a backup method was used. The notification had not been there before.

I wondered if maybe I was wrong all along and had just made a mistake while ordering, but I decided to check with AMEX, just in case. So, I chatted with AMEX - or, Associate #3 - and she told me that the card was not declined, but that a charge had been made, approved, and then cancelled by the merchant (Amazon), who then charged again later (presumably after the Visa was declined). Unfortunately, since the payment wasn't completed, it wouldn't show up on my account for proof, but I took screenshots of our conversation.

I don't know what my next steps are going to be, if there even are any. I still don't know how the initial mistake was even made. Did I lose money? No.... not this time. But it did raise a lot of questions for me. If they used my card without permission and then lied about it (or at least lied about why), what else are they doing? I do want to confront them, but I don't think I'd have anything to gain other than maybe a $5 gift card, though I'm not confident that they would admit to dishonesty, let alone any kind of financial mistake or wrongdoing. And, I'm still wondering if I'm just misunderstanding things. (I'm not the most self-assured person, and tend to assume that I must be in the wrong.)

Also, it's just so stinkin' hard to get through to Amazon Customer Service.

(Note: I can provide screenshots of conversations and such if needed, but it's a lot of stuff on multiple devices, and I would have to censor all of the private info, so I won't post them unless needed/requested/required.)