They don’t owe you or anyone an explanation. They don’t even have to make anything for anyone if they don’t want too. So don’t be rude. The staff are not bots and are real people doing what they are supposed to do.
Most companies don’t know when something is going to be done until it’s done and ready or will acknowledge it and tell others due to the fact that if they put out a timeline and missed it, they’ll have a lot of mad people they have to explain too etc.. or negative comments like yours.