bad service and giving away my account numbers to poeple I don't know.

I tried applying for a Datsun go+ cvt as on the ad it was stating the insurance was free for 12 months and the repayment was concluded by the sales manager was R3200.00 including insurance with Nedbank than I agreed on the but Mohammed Hussain Kara came back two days later telling me now the repayment is R3900 excluding insurance, I was very clear to him that in that case I am no longer interested but now he just called me telling me if I am not interest I must call insurance company I DON'T EVEN KNOW THE INSURANCE COMPANY. but now Mohammed keeps telling me I must call them. I am not happy with him giving my information to third parties and my account number not is not safe cos of this dealership.