STILL WAITING FOR CELLPHONE

Hi, I did an upgrade on the 27/08 for a microsoft lumia phone, received the phone on the 28/08. Took it home and it started restarting all on its own and the second simcard port was not working. I phone the call centre on the 01/09 and ram couriers feteched the phone on the 04/09. I phoned the call centre on Monday 07/09 and they told me that I must call back on the 08/09 which i did in order to do a new upgrade for a new phone. I di the upgrade with a lady by the name of Jenniffer and it was for a Huwaei P8 lite, she advised me that everything was in order and that I would receive a delivery soon. When I called the call centre again to get a ref number in order to trace the phone they said that they had no stock. Jenniffer called me back after I got in contact with Cell C via Facebook where I laid a complaint, she advised me theat there was no stock and that she will update me as they were going to receive a delivery by the 12/09. I called her this morning and she said that they still have no stock of the phone. How do we keep doing business like this even the agents do not keep to their words and I am very upset because I am now left without a handset at all. I am disgusted.