Worst service ever received

I went into the Chatsworth store located at the Pick n Pay mall and requested an update on my contract. I was advised that my contract was due for upgrade. I proceeded to upgrade and at no point was I advised that this was an early upgrade or that there would be a fee to be paid. At the end of the month my account was debited by R2300 extra. This was two months ago. I have tried numerous times to have this resolved and no one seems interested in giving back my money. Terrible service.