Vivint  Ripping Off the Elderly Provo, Utah

My elderly mother moved into an assisted care living facility. She had Vivint Security at her rental. She hasn't lived there in over a year but Vivint is still taking auto payments from her checking account. 

She mailed them a letter to stop service. They responded that they needed a letter from the facility. She had the facility send a letter. They're still billing her because they want to talk to her on the telephone to make sure she wants the service stopped. But the number they are using to call was disconnected when she moved out.

She can't remember the password that Vivint needs to make changes to the account so it appears they are going to keep on billing her. They did offer to move the security equipment over to my place and transfer the account to me. But why would I want to do business with a company that takes advantage of the elderly?