Got charged £60 by Ryanair for a bag I’d already paid for – any advice or similar experiences?

We paid in advance for a 10kg checked bag with Ryanair (it shows clearly on our booking). At the airport, a staff member told us we could go straight to boarding as if it was a carry-on. When we got to the gate, we were told it wasn’t allowed and had to pay £60 to check it in. Man at gate jumped straight to us needing to pay and didn’t bother to even sort or help resolve the issue.

So we basically paid twice for the same bag. I’ve complained to Ryanair and they’re “looking into it,” but has anyone else dealt with this before? Did you manage to get a refund?

I’ve complained to the bank so hoping they might be able to do something