I was an Amerigas customer years ago. I wanted to switch to another (cheaper) company and asked Amerigas to come pick up their now empty tank so I could have the new tank delivered.
They demanded a $150 fee to come get their tank. I argued with them that it was their property and if they wanted it back they should come get it, but they thought they had me over the proverbial barrel; without their tank being moved out, I couldn’t get a new tank AND they would charge me a monthly rental fee. My husband knew a guy with a flatbed truck equipped with a winch. We called him; he came and removed the tank.
We left the tank in the parking lot of an abandoned building. I called the sanctimonious jerk I’d spoken to @ Amerigas the day before and when I identified myself he asked, “So, are you ready to pay the fee NOW?” I said, “NO, but would you like to know where to find your tank?” Problem solved.