contract update

hi. i have a contractor with cell c which i took in May 2013 which was supposed to end in june this year. in march i recieved an sms telling me that my upgrade is successful while i didnt make any upgrade. i called the costomer care to report this. they told me to send an afdavide and ID copy to the ***** department. i did that but after noticing that there was no feedback coming from them i had to call and ask. they told me that they never recieved the documents that they requested, that was june. i had to send the documents again in june but still nothing has happened to the case. i called again and they told me that they are waiting for the upgrade department to send them the upgrade documents that they said ive signed and they havent recieved them yet. up until today they havent recieved those documents. i wanted to cancel the contract with them and they told me that i cannot cancel because they see that i've upgraded to a new phone. now i am being charged for a phone that i dont have and dont even know how it looks like. please help.