Following a detailed discussion with Martin, the Technical /Product support head honcho at Gaslow I can report the following :

Shell are closing their LPG sites following” a tiff “with Calor Gas which resulted in their firm Autogas making all 50 staff redundant in Feb 2020.  BP however have a little brighter news, yes they are closing LPG pumps on the sites they own outright, which leaves about 92%of the  franchised BP sites still running.  Currently there are 692 sites in the uk just now. It has been on here before , but for an accurate guide and thus do not rely on media gossip is a site called  reasonable accurate information provided day by day user entry.

It is recommended that you try and use in on a web based connection, and not just the app on the phone line.  Another site is for Europe. 

We may be going towards electric vehicles, but 12 volt will not power our fridges and cookers when no EHU is available . The other reason for restrictions is the Covidiot Types filling individual   calor bottles, in particular the recalled ‘lite’ bottles. Please don’t do it. The lite bottles rust out from the inside. This is why they are hardly ever sold ‘filled’ nowadays.