It's probably locational and possibly the time of day. Since I understand cleaning them are a pain, certain locations may not prioritize it properly, or the downtime is always when you would go. The one by me for example has been down all of the 10+ times I've asked for something, but I know family members have gotten some ice cream there, so it's not like permanently busted or anything.
What if someone says "no no" or "no dont". That conveys a negative response despite being two negatives. Granted these aren't proper English or full sentences, but it's something you might say