How is it decided who gets a rating refund?

Lately, rating refunds have become very rare for me. In the whole of 2025, I got just two refunds so far even though I do have defeats in my game history where the opponent was banned later. In one of those games (from June), I even was the last opponent they played before getting banned, yet I didn't get any refund from that game. This makes me wonder: How does chess.com decide who gets a refund and who doesn't? Obviously, they don't refund all recent wins of that banned player (otherwise I would have got a refund for that game I mentioned). Do they check all recent games individually and decide on a refund on a case by case basis? Seems a lot of work. Or are players who report more likely to get a refund and everyone else only gets it if they're lucky?