Was I wrong/rude??

I’ve been applying for jobs. I saw one in a nursery. I’m skilled and have the qualifications etc. I’ve worked in nurseries before and I know that the ‘norm’ is to offer childcare discount to staff. This is why I applied to a nursery job, as I’d need childcare whilst working. The day after applying I got an email from the manager inviting me to an interview. I emailed back saying how pleased I was, and asked whether they offer a childcare discount to staff as financially I couldn’t take the job without this. She then emailed me straight back saying sorry the position is now filled. It obviously wasn’t filled because this all took place in such a short period of time and the nursery only reopened today following Christmas/New Year!!

Was I wrong to ask this? Was this rude? I’m not too bothered about not getting the job but I do feel embarrassed about it all, and I’m left feeling really confused as to why I couldn’t ask a question that is important to me actually being able to work?