didn't be honest about what I going to pay...

Hi there, I have not the sales persons name, it was a guy...anyway, I go there for the upgrade of my phone/contract, I did have a weekend contract, but know the sales man tell me on the smart phone that contract is not excist anymore, so I choose the cheapest contract the Smart small one, then he keep on saying I must take the LG G4 phone, and not the Samsung he say this LG phone is a good phone, and not expensive, and they on a special and they got only one left, ect ect. so I beleave him and took the phone. I asked him how much am I going to pay monthly, so he say, my contract will be around R400.00 plus my insurance, together it will be R600.00 what is find for me?this was in July..., So when I got my acount, what a hell of a shock!! is was almost R1000.00.. so I phone vodacom, they then tell me they can't help me, I have to go to vodaworld in Midrand, its far for me, because I stay in Pretoria North. anyway I was there on Saturday, the 15 Aug 2015, the lady who help me check on her sistem and told me I've also going to pay for this phone every month for the 2 year of the contract.... so its another R300.00, so they lie to me, I want another phone,and not paying for it