Cocoa shell mulch

Does anyone know of a source of supply for cocoa shell mulch? Either national (by mail order), a national DIY/gardening chain store, or local seller in the Uxbridge / Harrow / Watford area?
I used to use this in my garden and found it brilliant.  I've recently taken on an allotment and would like to use some to keep the slugs and weeds at bay.  I believe most DIY stores stopped selling it because it is poisonous to dogs, but as our allotment is well fenced and doesn't allow any dogs, that isn't an issue.
Thanks in advance!

You can alos get it from here
http://www.greenfingers.com/
In fact, I got some free - I ordered a greenhouse heater and received a bag of cocoa shell mulch. I told them and they sent the heater but failed to collect the mulch.