My bill is too high

I recently got my cell phone upgrade, which now recently got my statement, which states I need to pay an exuberant amount of R1388.14. I then called Telkom billing department which I spoke to a Kabelo who was kind of helpful though he doesn't believe in the statement that \ the customer is always right ". How come my bill will be so much what am I paying for? I am on the My Plan 100 which is R199 per month. So Kabelo advised me that Sell Direct which is Telkoms outsource sales department made an error they upgraded my phone but I am still paying for data & the upgrading of my mobile. So basically my phone got upgraded not my plan. I then advise Kabelo this is not the conversation I had with Sell Direct I should be on the My Plan 100 which is the Summer Deal special which is currently running.There is no way I can afford so much money for a cell phone.I can't get hold of Sell Direct they always hang up on me"