Going out on a limb here, I highly doubt you will get any, you aren't entitled to it. It was a free event and it sounds like swapping to old client avoided the issue.
Also they can't really tell who had the issue, be realistic.
Wonder what was I doing on the 24th? Well lets see, we had 8 cows calve + the usual milking morning/afternoon, so not much wurm time there, what about the next 3 days? We then had 16 more cows calve, so obviously I was quite busy and didn't get much out of this event.