Its still there. It won't work. Let's remove it.
Looks like most of the refund code has already been removed in https://github.com/mozilla/olympia/commit/ad7b8e4f84c787c20c0c34d874f8e3aa0d047963, but "git grep refund" still returns some CSS and other stuff.
That's excellent Berker Peksag, thanks for triaging this! Do you want to have a go at finishing the removal?