Family Mobile Walmart - Family Mobile cell phone complaints Miami Florida

I am also receiving payment due notices from Family Mobile in Miami, Fl.  The account was closed in April, 2017.  When I call Tracfone, Walmart and T-Mobile they all say they cannot find an open account and we do not owe anything.  BUT, we keep getting a monthly bill for $55.30.  I even went to Walmart and the service representative tryed to talk with a supervisor and she could not find anything.  At that point, this supervisor transfered me to Family Mobile and handed me the phone;  when I asked for a street address, the person on the line hung up.  This is very trying and I was just wondering if anyone else is having the same problem.