Cancellation of contract

I was due for an upgrade on the 13th of May. I did the upgrade online, and then I received a call to continue with an upgrade process. The consultant who assisted me with an upgrade was Revinah (if I remember correctly).

I wanted the grey IPhone, but she told me it was out of stock and that only the blue one was available. I agreed to take the blue one. She also told me that I would need to make a once-off payment of R340. When I asked what the payment was for, she said it was for the device. After that, I would continue paying my normal monthly instalment.

After waiting a week for my phone, I called to follow up. The consultant I spoke to was Sanele, told me that the phones were out of stock but they'll be available on Friday last week.

When I called again today, I was told that there were still no phones available. I then requested to cancel both the contract and the upgrade. The lady I spoke to said it was not possible to cancel the contract because it only ends in October. I have to pay this R4 something until October

I am now confused because I was under the impression that my contract ended in May.why am I being told different stories.