I get my lpg from a John deer agricultural dealership. I refill my bottle for .72p per ltr, however they have a faulty clock on the pump and in cold weather, you can put about a 45sec of gas in before the clock even moves. I have told them and they don't seem to care, I recon I put about 4ltrs in that does not register. Also if you say you have put in 8 3/4 ltrs they always charge for 8ltrs.
Roy