Sounds like they need this position filled immediately, so are just putting anyone who has put a CV in forward (within reason) so you may still get it, dont write yourself off yet, you obviously had skills they would like within this role.
incorrect, one position needs to be filled by december.
job has been advertised for 2 months.
i just lucked in when my cv arrived for another job,
perhaps a job as a cv writer might suit me better

Just caught up with this thread.. (don't visit off-topic much)
Dude, sorry to hear that you think it went bad but as said, don't write yourself off yet... Been in exactly the same position. Went for an IT job I wasn't qualified for, started with simple technical questions that I knew the answers to but gave the wrong ones!... Opened my mouth before thinking. Also had hard questions I didn't know the answers to. Beat myself up after the interview but was offered the job a week later because of previous experience, positive attitude, interest and the fact I apparently demonstrated promising capability. Mugs!
Joking, I proved them right.
Wish you the best and hope you get it if you really want it. 
Cheers shaun, and the others, not written it off, just being realistic, if something comes of it then great. if not, its back to mass applications for a job of any ind just to get me moved north