As you've said, AIBU was not the right place to post.
Having read your updates, you are clearly having a very difficult time
. However, to be fair, all the first posters replied before you put any of that in.
Many posters will read the start of a thread then leap to the end, so they are replying to your OPtoo, and, of course, are right that YWBU to expect your dc to attend for nothing, or unexpectedly.
So you understand, Nurseries have to proved the right ratio of adults to dc. So, if your dc is 3, then 1 adult can look after 8 dc in a room, but, once a 9th is there, they need a 2nd adult. It might be, than when you had your difficulties before, they had 'space' within their ratio and very, very generously said they'd help you out at that time, because of that circumstance. Now, it might be they don't have space in that ratio, and your dc would take them into number needing an extra adult. Or, it might be they felt you had misunderstood that it was a 'one off' when they helped you before and that you didn't realise they had to balance their books.
Please leave the thread and go and look after yourself now, as there will no doubt be others who reply to the OP and don't read all your following posts.