Our local health store carries it so you could try any good health food store probably. They may even order it in for you if they don't already carry it.
if you go onto their website and click on stockists it then brings up a drop down box where you can click on the area you live and it will give you all the stockists in the area, including independant stores
Tesco no longer stock Lizi's granola in my local store either but anther store 5 miles away stocks it.
Also, Tesco still show the Original version as being sold online.
As I understand things, Waitrose is a good place to buy Lizi's gronola products but we don't have one very near by to us.