Breach of agreement

Beginning March I entered into a agreement with Cell C for a R289, 500mb per month laptop deal. I received confirmation that it has been approved and that delivery will be made. After no delivery I called only to find out that the order was not placed although the system reflects that it has been approved. It was then said that the sales lady, Nonhlanhla gave me a deal that was only on a special for February month. She confirmed with me that she knows that our agreement was for this deal and that she will sort it out. I have send e-mails and called the call centre with no joy. I have been a Cell C client for many years with 2 other contracts with them and am very dissapointed with the way I have been treated this time. They have never before breached any other contract that I have made with them and I hope that they will not keep on doing it with this deal. I do not want to receive a call saying that they are looking into the matter because I have heard this numerous times now. I want a call to confirm that they will deliver the Laptop today , as promised, on the price and deal that was agreed upon.