Breach of Contract

In Feb 2015 CellC contacted me to upgrade my current contract I have with them. The sales lady went through all the steps they usually go when giving you a contract. She explained to me that I will get 1GB of data, 100min, 100sms per month for a certain amount. I confirmed with her 5 times to make sure that I'm getting my 1GB of data of the amount specified. Every time she said 'yes that is correct' and it was even stated in the Term&Con. On the 1st of June the upgraded contract kick in, but to my surprise I was on a package of only 100MB per month, and not the 1GB as promised and agreed to. I called CellC on the 5th of June to try sort it out, but until today the 22 of June this issue has not been resolved yet. All they keep telling me is they are looking for the recording, they can however find all my other recordings but that specific one is missing it seems. CellC is responsible for this, they need to sort this out as soon as possible. They are not giving me the contract that I agreed upon. I've called them about 13 times since the first complaint I made on the 5th and still no feedback other than they are looking for the recording.