no response an bad attitude

End of May 2015 I contacted vodacom 3 time's requesting my settlement amount an on 3 occasions I received the same amounts, I also asked after payment is made should I contact vodacom an inform them that payment was made an I was told its not needed.I paid the amount an a week later I received a snail mail from MBD stating I owe them money. I contacted them to inform them that I have paid vodacom already an nobody at vodacom said I was handed over. My question to them was why do I now need to pay them a full amount when I have paid vodacom already. I was sent back an forth an nothing has been resolved. They keep calling an I keep asking the same things an in the end I get treated so badly , I even tried asking for a manager but they refuse to let me speak to one. Its almost November an I am still struggling to resolve this issue an by now my account has been increased due *********** staff .This is the worst people to deal with