Superior Propane

I contacted Superior Propane to deliver me a propane bottle and have it filled. They brought me an uncertified propane bottle which has sat at my place since 11/04/19. They have since been harassing me with phone calls and threatening my wife with collection agency by phone and mail. I tried going to their office to remedy the problem but no one seems to care. They since have mailed a bill asking for payment on rental of this unusable bottle. As I said I tried several times to speak with someone in the office, no one seems to care to get back to me. Tried calling head office.. again no return calls. Now threaten me with collections. I still have the bottle which I even offered to return myself, no one is interested but they will bill me for it. Still have yet to get propane and the empty bottle remains in my property that expect payment for?? I don’t want their service but expect the bill to be erased and collections contacted to withdraw any charges under my name. Come take your bottle back and I may want to charge them with harrasssment. Thank you. I need some help here please.