Customer 23 (rude and stupid)

So a customer came in, someone made an exception for her because she was paying the bill. Instead of checking id they sold her an ipad air 2 with service on it without checking. It turns out it wasnt her account it was her sisters account. So 2 months later she came in and said their was a billing issue. Of course I get her, so im checking and shes not the account owner. Luckly for checking a bill I can make an exception using security information as long as I dont make any changes. So im checking and ot all seems good. Shes not even disputing the amount of the bill so I ask her, if theirs a billing issue but the bill cost what you expected then what is the problem? She said well I bought an ipad 2 months ago and its not my account. So I want the ipad charges waved, the ipad service disconnected and the be refunded any cancelation charges because I was not allowed to sign this agreement it had to be my sister since its her account. Meanwhile this tablet is literally right in front of me on the desk and im thinking..... really?.... so you want us to gove you a free ipad for no cost whatsoever because you committed fraud on your sisters account. Alright ummmm yeah NO. I dont understand why she thinks she can get away with that. Then she threatened me with a lawyer and im like all I did was check your bill but thank you for mentioning a lawyer because once you mention a lawyer my company gives me the right to no longer serve you with no questions asked and no consequences.  So thats what I did. My manager delt woth her and turned her away. She called back a few days later and I answered the phone because im suppose to answer the phone when I can. And surly enough she called asking if she was credited back charges. When I found out it was her well let me check and put her on hold. Told my manager sge was on the phone and he asked me if I could just take it. I told him nope, she threatened me with a lawyer and I didnt even do anything so she can eother wait for you or hang up. So she sat on hold for 45 min. He forgot about the call and was like shes still on hold??? This cant be good. So he goes to answer and she hung up literally roght when he went to answer. An hour later she called back and I answeted again. Oh yeah you again one moment and shes on hold. My boss left already so no one takes the call. She sat on hold 45 min and the next day she called back and he happened to answer and took care of it. She made an unreasonable and unrealistic request and threatened me so she receved no service from me.