It was a 175 so a regional crew, very likely not well versed in actual United rules since they don't really work for united any way. 175s dont have ovens so you missed out on a cold sandwich and salad.

I would make the case that you upgraded based on dinner and likely would not have if the actual facts were known (Its a stupid basis for upgrading but it might serve you). I would then angle for the upgrade $$$ to be refunded since they didn't meet the obligation as advertised.