Took days to process my ipad replacement

Hi, here was the story.

I sent my ipad to the apple store(ireland) to service due to earphone jack is not working.

They checked and promised replace my ipad in couple days.

But now, after 18 days I still haven get back my ipad. I went there 3 times and ask for it, they said the apple got no any updates and they don't know what was happening.

So what should I do? I kinda worries now.