This has happened to me several times PM. UA used to be really good about giving "downgrade kits" and usually they included SWUs, CR1s, RCC passes, drink/meal vouchers etc. The last one I got for a downgrade IAD-NRT was 2 SWUs and 2 RCC passes. By the way, I never asked for anything, a GA would just give the kit to me and apologize. I was always happy with what I was given although their generosity varied over the years.