My train back from Köln last weekend was cancelled, resulting in me having to get the next train, thus losing the reserved seat, then the train came in backwards, so my first class ticket was useless as I didn't want to run 8 carriages. But I did at least get a seat, Eventually, by the time I got home, it was nearly 2.5 hours late, on a 3 hour journey. NS (who I purchased the ticket through), refunded me in 4 days, 50% of my ticket price.
J