Telkom renewed contract without my permission

My contract expired, I went to the Istore to upgrade only to find that the contract has been renewed without my permission. I contacted Telkon and the agent was rude and dropped the call when I asked why can't they provide me with proof that I requested an upgrade. I then went to Menlyn to request a cancellation and they told me that they cannot cancel the contract because there is no proof that I did not request an upgrade. Is it, not Telkom that should provide me with the recording of the day when the contract was renewed?