Founded in 1938, Primagaz is a long-standing French player in the distribution of propane and butane, both in bulk and in bottles. It was the first group to obtain authorisation to distribute gas on the grid in the 27,000 municipalities not served by natural gas, helping to balance the energy mix. Since 1999, Primagaz has been the French subsidiary of the Dutch SHV Energy group, which has 30 million customers and 14,000 employees in Europe, Asia and Latin America. It certainly appears to have a Belgian arm, a French one and a Dutch one (possibly more?). Many of the French distribution points (garages and supermarkets) are now going over to automated bottle swap facilities available 24/7.
And you can get them delivered in the UK it would seem - outdoorxl.co.uk appear to offer home delivery (Dutch sourced) refills for 2.5kg and 5kg bottles (the latter half the price of the former...!!!), or the blue 5kg bottles from their shops only.