I used Ferrell Gas for a couple years, but they required me to:
a) Pay for the fill up before they filled it.
b) I couldn't even pay for it until I was sitting at about 10% full.
c) They only showed up once a week and so I always ran out of propane before they showed.
I switched to Bailey Propane and love them. They top me off during the month and if I happen to get low in the winter and need them to show up out of cycle, they are there. And I was paying less per pound than I was with Ferrell.