Paying for a phone I never received!

I have been due for an upgrade since Feb. I could have never upgraded as Telkom never has stock of the phone I want. Telkom advised that I need to go to the Istore in Centurion and process my upgrade there. I went to the Istore did the upgrade and as I was about to finalize the paper work and notices the Istore contract prices were much higher than the prices of telkom so I just left the phone there and advise them not to process the upgrade, however the upgrade was still processed without me taking the phone, this was in May. Since then I have been trying to cancel the upgrade with telkom and the Istore with no success. Telkom blames the Istore and Istore blames telkom meanwhile I am the one paying an expensive telkom invoice every month and I don't even have the phone. this is absolutely disgusting as this is now my 4th year with telkom and they are not prepared to meet me half way. I want this contract cancelled and converted to prepaid and my money that I have paid since May refunded. This is a constant struggle and I really don't understand how cancelling a "incorrectly processed" upgrade can take almost 4 months without any success. ref number provided by IStore Centurion: ***.