Taken eye off ball with J GAS - advice please

Rhino666

Hi

I signed up to Lima Gas just over 4 years ago - no standing charge and cheap LPG. J Gas(Johnston Fuels) took over Lima sometime in 2016 and to begin with the change was seamless with cheap gas but now gone completely pear shaped.
I do live in the middle of nowhere, TQ7, only use about 1200 litres of LPG delivered once a year and am aware that wholesale prices have risen significantly.
I got my annual delivery in November - 1128 litres @ 41.6p a litre + VAT, just avoiding a price rise of 5.23p a litre.
Never paid a standing charge and just received an emailed invoice for £63 for this years tank standing charge - do you think J Gas are trying to tell me something?

First question is does anyone know why J Gas have suddenly sent me a retrospective tank standing charge bill for this year when no such charge paid from when I signed up in September 2014.
Secondly, bearing in mind low usage and location, can anyone suggest where I might get a better deal.