Quotation approved is a total Reap off

Hi Hello Peter, i app**** for a loan at Nedbank on the 1st week of March 2016 and they phoned me to go to the nearest Branch.They offered me R80000.00 monthly payment of R3150.00 and because i was in need of the money i agreed to that amount even though i was not happy. I filled in the form but the application took over 3 weeks with quieries and the lady at the Branch struggling to get the documents on the System. Then the consultant adviced me to apply again. <br> Then i filled in the Online form again on the 8th of April and the afternoon a Consultant phoned me and offered me a new loan of R100000.00 at a Monthly payment of R3100.00 i was so happy about the Quote that i immediately accepted it .Then Saturday morning i receive an Deposit in my Account and im excited about it but it was less. Then i thought i will contact the Nedbank on Monday since its weekend now. Now Monday i receive an email showing they give me R80000.00 IM NOW CONFUSED ?? Please explain this Reap off how can i agree to pay an expensive Quote when being given a better one at a later stage. What i want is that they thansfer the R100000.00 with better instalment Quote they offered me. Where i my Consumer rights ?