Vodacom contract

I did an upgrade with vodacom then the person who helped me with an upgrade has resigned and now the contract its not what i signed for. I went back n forth to vodacom shop..they cant help me and i did call vodacom contract centre.. they send me to back to vodacom shop..i did an upgrade on november 2019.. the person who helped m has done his own things like red select lines n put five lines on my contract..i was suppose to pay R599 for the phones now it says i must pay R1600.. i need vodacom to interven on this issue