I've just checked the role and it was posted to our careers site 14 days ago. It may be a case of the role auto-closing after a set period, but let me look into this with the hiring manager in the morning.
Based on the HN post time, you will have posted your reply about 6.30pm UK time. I'll ask someone in the team to find your application within that time frame and contact you on the details you had applied with.
If anyone else has a similar issue please let me know, we don't always get sight of issues like this and it makes for a really bad experience.