AFBUCHER in the UK even my local Tesco sells milled chia, so does Holland and Barratt and most health stores.
Linwoods is a big suppliers Here or there is a choice on Amazon and almost too many sources to list
Sure it's not the exact same brand, but it's all 100% chia. Some (like the chia seeds company) mix light and dark chia seeds like Mila too, but even if this does give the seeds a different nutritional spec, there's nothing to suggest it affects the pouch any differently anyway, and other brands are probably cheaper, so may be something you want to try.