Incorrect Billing

In April 2013 I took out a contract, Top up 135, at Game Welkom with cellphone nr ***. I could get a Curve Blackberry on this contract. On the same day my husband upgraded on his Top up 30, cellphone nr ***. He could get a Bulb Blackberry. To my amazement When I studied my account for the first time 2014 I saw that I pay R348, 50 instead of R198,50. On enquiry at Game, Natasha said that I pay for a Bulb Blackberry. Game Welkom on the day of upgrading, etc got confused and loaded the wrong phone on my account. A total of R150,00 per month was paid too much which is R3600,00 over 24 months. I upgraded on 8 April 2015. I spoke to Natasha at Welkom Game numerously for more than a year now. She confirms that the documents from Game was e-mailed to Vodacom who is now responsible for the corrections and reimbur*****t of R3600,00 on my account. After a year I am no further than I was today. I tried to phone Vodacom Customer Services but had to after an hour on the line waiting for a consultant had to put the phone down, for I cannot stay on line the whole day. Natasha in the meantime had an operation and could therefor also not be reached for a period of time.