I bought a Pi Zero last week from The Pi Hut, arrived in two days, they had loads in stock. Might be a problem with your local distributor? I'm in the UK so supply may well be better here than elsewhere.
I did get tripped up with the camera connector being a different size to normal Pis though, darn it.
[1] www.thepihut.com (I am not affiliated with them in any way)