Should I be offended at this?

So I applied for this job a while ago, seems like a winnar. So I have the interview and I seemed like a winner. So they never get back to me and I assume they somehow managed to find someone better than me. And then today I see the position readvertised.

WTF?

So I reapplied. But what's the deal here?!

you ALWAYS follow up a job interview with a call to see if they've made a decision yet. if nothing else it lets them know that you're serious.