Cell C *****

hello, Please help me . i had a contract with cell c fiber from January 2021 and in march 2021 they opened another account in my name on a place where i don't live at and started double billing me . i tried solving it with them for the past 5 months but no luck .i asked them to take what ever amount i own them and close my account so they took all they money but this month they sent me a bill for the place i dont live at and they want me to pay it . it means they want me to pay for something im not using . please help