***** on my vodacom account

Hi asked to be put on prepaid, insted the person from vodacom who was helpinh me upgraded me. I did not sighn any documents. When i realised that there is debitorders going off on my account i phond customer care and they inforemed me that i have been upgraded. I was told to send documentation threw to the ***** Dispute department and i did on 19 Feb 2018. I was contacted to say that they are busy with the investigation. On 6 March 2018 i was notified that my account was not paid and if i do not make payment my line will be cut off. When i phoned i was told that the ***** department never recived my documents. I sent it again and am getting no response. Everytime i phone i get promised that i will be phoned back but it never hapens.