Overcharged, No response? frustrated!!!

I'm writing once again! I upgraded my contract the consultant stated my suscb fee to be R149 as advertised. I'm being billed R219! I queried the charge, customer care says my bill is R219. Doesn't mke sense to me as I was denied a contract of R199 for S4mini but I qualified for R219? & my monthly statements stopped after the query. The consultant also failed to mention that I would be getting a pre owned devic which is so troublesome!!! I want the overcharge sorted so I can return the device. If I knew I was going to get a second hand s**** I wouldn't have renewed my contract. I guess the consultant pushed it to me for a reason. I'm losing faith in vodacom and will not renew my contract if I don't get my issues resolved. This is very unfair! To be overcharged and given a s**** handset without informing me!