binding contract with cell c is not binding

Good day. I was in the unfortunate situation of loosing my cell yesterday. I called Cell C to blacklist the phone and to upgrade as I was informed by one of the Cell C branches and the head-office last week that I am due for an upgrade on the ********** ..... I was then informed that my wife , who's cell is also on my contract with Cell C is also due for an upgrade. I spoke to a lady by the name of PORCIA TSHIBALANGANDA. She advised me that I qualified for the Samsung S9 + and on my wife's upgrade I qualify for the Hauwei P20LITE 64GB in blue with 150MIN, 150SMS'S, 150GB DATA and that I would pay R394.00 which included the R15 whatsapp bundle. We concluded both contracts telephonically as I did my previous contract with cell c as their calls are recorded. I too have a work phone that records so the whole conversation between myself and her was recorded. She then 10 minutes later calls me and says that she made a mistake, I don't qualify for that phone (Huawei) that the contract was closed on???????????? She wanted to offer me another cell worth less with less data, min and sms's as well as on a open contract and not a top up which I don't want. I closed a contract on the Blue Huawei P20 lite 150min, 150sms etc. When I told her this, she told me that there was no contract as I am suppose to sign a contract. So now I would like to know, how was the contract on the S9 finalized telephonically and the phone was already delivered and received, but the contract on the Huawei , that was finalized at the same time, has to be signed before it can be finalised??? I refuse to accept this and will take the matter up with the ombudsman if need be. I have the recording as well. I work in a financial institution myself and know that a recorded contract and conversation is binding. I have asked that a manager calls me back to sort out this situation. If not I will take this matter further. Please contact me on ********** 571. I will be waiting for your call. I have been a client with Cell C for almost 20 years and I would not like to have to take my business elsewhere.