Incorrect Billing

I recently upgraded my cellphone at Southgate SABC0206 Mall 296G (2015-07-04)and was assisted by Hjordis Martin. The cellphone of choice was a White Sony Experia E4 which I ordered about two months prior, but the upgrade could'nt be completed because of the MTN strike. Jordis contacted me when the phone arrived and she confirmed that the price is still the same (R139.00). I than went to the Southgate Store to complete the documents. Jordis assured me again that the price would still be R139.00. I showed her the price in the latest brochure(R184.00) as I wanted to take something cheaper,she told me not to worry about that. To my dismay I was debited R419.98(2015-08-31),R184.00(***).I sent Jordis numerous emails, requesting her to rectify this.She only greeted me in the 1st email (email without compaint), but when I forwarded my complaint, she never rep****.Iam infuriated by this as I was misled and now I dont get feedback. I need this Error to be recitified immediatly. I need this funds to be reversed and my Tarrif to be changed to R139.00(100 min,200 sms, 300 data).I've had this contract since 2004,with no missed payments.I dont deserve to be treated like this!!!!