Is there other propane companies in your area? Talk to your neighbors and friends see if who has the good reputation in your area.
If your company isn’t one of the recommended ones then it is time to switch. Have them empty the tank and give you a refund for that gas. If the tank is theirs have them remove it. Arrange for the new company to bring in a tank and fill it to your specifications. Stipulate in your contract that they are only to fill it per your request not when they feel like it.
Good luck. If they give you grief go up the change of command by talking to a supervisor, then a manager/owner.
We had one of of our local propane companies decide that they were going to dump the high priced product into all of their customer’s tanks before a price drop. They lost a lot of customers as a result of that action. Numerous people were threatening to sue them for their actions.
Yep. I intend to huddle with the neighbors in our small enclave, after this supposed blizzard moves through. I suspect, though, that many might not be paying attention like myself until I got fed up with the bills.