Oh well. Too late now. For next time, do they do O/W or just R/T? Also, can you book online, because all I saw was a phone number.
Can't recall. I needed Thalys (which they don't do), but played around there a little. The avail seemed to be linked to the rev price, so its pretty safe to assume it wasn't avail on your dates.
Just a random fyi the ES serves kosher meals.
You might be able to refund the ES if avios is avail.