FAULTY PHONE DELIVERED!!!!!!!!!

I am absolutely appalled by MTN and there online services. I did a upgrade telephonically and received the device on Friday the 4th of May. From the moment I switched it on it started jumping from screen to screen, typing on its own and making calls on its own. I have called every single contact number for MTN possible and been into Bayside MTN , Canal Walk MTN and TableBay Mall MTN. I have called MTN direct numbers and get the same response from all. Call customer care they say to go in store, I go instore just to be told they cannot assist me and I must call the customer care. I have been dealing with this since I received the phone on Friday and it is now the 6th day!! I am nearly at the end of my 7 day out of box (as per the terms and conditions of MTN) !!!! they just push you from place to place to ensure you will not make it within the 7 days just so they do not have to be accountable and replace the device. So quick to get people to sign and take out a contract yet these people cannot even adhere to there own TERMS AND CONDITIONS!!! I need a response ****** quickly because I am entitled to a brand new device!