The worst customer service ever

I’ve read other reviews here about Supersonic and I have to agree with all of them. In October I requested a migration and the old line to be canceled. In November I was charged for 2 lines, the new and the old. I enquired and they said they will cancel the other line and rectify my account. Now in December im billed for the one line which is good, it means they canceled the old line. But my account is still in arrears as I still owe them for the non payment of the old line in November and yet they were meant to fix that. A lady called Noxolo is apparently handling my account. She has done nothing and it’s almost 2 months and no one else can assist me since she is handling my account. She wrote a note on the system that she has not received proof of payment for her to do credit note. But why do you need proof of payment for 2 lines when I was charged in error for the old line? She never calls me and just writes notes on the system. My account is up to date for the new line, can Noxolo please update the error of being billed for the old line and send motivation or whatever so that billing can fix this or is that too much to ask? S***