Charged for online upgrade

I was advised by the agent that the online upgrade via the phone is free as well. When I received the invoice and statement and I noticed that I was charged R150. I queried it various times but to date have no written confirmation (as requested) that the monies will be credited. I was only told on the phone that I would get the amount refunded. And I had other problems with this upgrade, it was shocking (no SIM card received; delivery address wrong therefore it took much longer to receive the phone and the postal address was then changed to the delivery (work) address !!).