not impressed

I purchased my i20 from the Paarl branch in 2011 and complained about a few things on the vehicle I was NOT happy with. The vehicle went back and fourth a few times as I work in the Southern Suburbs. Eventually they referred me to the Bellville Brach when my vehicle was due for a service. I keep complaining about the steering wheel that makes a clicking sound that is only getting worse. All this was put in an email to the dealer in Paarl. The problem is they keep taking my vehicle and when I get it back it does the same thing....NOT VERY HAPPY!! I am at my wits end. The vehicle is still under warrenty....I need assistance in taking this further please.