OVER BILLED AND SUDDENLY NOBODY CAN HELP

9 September i went in to the Loch logan Vodacom to do a change of ownership on a contract that was on my sister in laws name and take out a new contract on the existing number that is due for an upgrade.Frankie assisted me with everything .I paid in the branch for my change of ownership and sim swap. Had to wait three days for the sim swap. I went in again explaining that the sim swap has not gone through yet. Where the other consultant explained to me that it was never done. End of september my siste in law got billed for R905 i went in to ask why they have billed her if it is on my name? i got the next invoice in October saying that i now have to pay R1001 whitch is ridiculious the contract that i took out is supposed to only be R395 a month. This time i went to the branch in second ave where another consultant assisted me and said that they had made a big mistake he will see what he can do the next amount that will go off should only be R395. I tried to call Frankie multipile time where they always tell me that he is busy i should leave my number he will call me back.Which never happend. I then called head office explaining how unhappy i am with their service and that they need to fix all this ****. She said that she will get back to me about what is going on with the amount that they have billed me. Never heard back from head office. I went to Fichardtpark vodacom hoping they will be able to clean up all this mess. I was assisted by Marne she was friendly she called frankie explaining to him that he has been charging me for the wrong contract all this time he said that he wold fix it and call me. He never called me. I have tried to call him multiple times with no response i just get the same message over and over again that he will get back to me. I called Marne today 15/11/2017 saying that Frankie has not called me and when i phone the branch he is always busy. She said that she will call him and find out what is happening he was suppose to call me she has told him a few times to call me. I received another invoice saying i have to pay R1749.09. What is going on with your service and no one seems to be able to sort this **** out.FINALLY i went to the langenhoven vodacom branch where i was assisted and informed that they have CHARGED my sister in law again . What kind of service are you giving to the public and where is your cutomer service.When they make a mistake i have to pay for it and i will not!!!!!!