I have an order where I partially refunded an amount then did another refund for the remainder. The order was never shipped. Two credit memos for the full amount but the order status is still showing as 'processing'. I thought when you refunded the full amount it automatically got changed to 'closed'?
It's really hard to tell from here, so there may be a couple of variants, as with the native Magento functionality your order must be closed now.
1. A third party extension or a customization is intruding into this process.
2. Your order workflow (see Magento docs) is set this way (check your order state and status workflow). For example, someone assigned order status processing to order state closed. Or the refund wasn't fully completed (say, for two products out of three were refunded).
Hope that helps or at least hints into the right direction.
It's still showing as 'processing', the full amount was refunded.
Our workflow is to set the status to 'closed' once a full refund is issued and credit memo created.