It just sounds like y'all got Cast Members who just didn't want to put effort into pouring water, which is just a shame. If it happens again, just ask directly for a Regular or Large cup of water, if they flat out refuse (which I really doubt would happen; for heaven's sake, it's just tap water), ask for a Manager, as that's just flat out against Service Guidelines and is something that the CM would need to be coached about to ensure a better experience for future Guests.