I had a couple of Amazon active card checks for £1 that took ages to refund. In the end, I contacted Monzo Support and they refunded the money, but the original transactions show as pending.
I flagged this up with Monzo Support also, they’ve said the transaction is showing as cleared their end. They recommended uninstalling and reinstalling the app, but it hasn’t made any difference.
Very strange.
Give support another chat and see if there’s anything else they can do to help 
Can confirm this also for me. Shows in statements as pending even though it’s not. No big deal, just unsure why Amazon have to keep putting these checks on cards. They seem to be random too, not just when you add a card or when you make an order or just before your item is being paid for.
Tried logging out and also uninstalling but still there.
This does seem to be normal for these transactions. I’ve never seen one left in any other state. I just assumed this was the way they worked.
This is not a Monzo issue. It’s an Amazon issue. It already happened to me on my Payoneer account the first time I used my Payoneer card on Amazon. It’s still sitting on my dashboard there. So I’m going to leave it for now, and chase both with Amazon when I feel that bored that I could spend the time chasing £1.
I just found this info on the Amazon UK site. https://www.amazon.co.uk/gp/help/customer/display.html?nodeId=201895660
This is not just Amazon but, I’ve an ATM transaction that got refunded and then money taken out again (three transactions) with original charge still showing as Pending… This is from October 2016. Every Single transaction I have which has been refunded still shows as Pending on my app.
Yep every single duplicate Tesco transaction that I’ve ever had a refund for, is still showing a pending transaction on the original duplicate.
It is quite confusing looking at it. Must be a better way of presenting this.