Unsatisfied Kia Hatfield customer

I Took my vehice for a service last year August while it was also making a weird sound Kia Hatfield adviced that theres more to be fixed on the car after a full inspection by the mechanic. I agreed to what needed to be fixed therefore my warranty paid a certain amount & I had to pay in the rest which totalled to R34 000 something I waited for a month for my car & after collecting my vehicle 3 months later it was doing funny things as it was still under the warranty of what they fixed in August I returned the vehice they then adviced that they will be doing a claim from Kia SA to replace the same clutch kit they put in in August nd that I have to pay another R28 000 for a different part I disagreed because I won't be spending another dime 3 months later I asked to put my car back together nd return it in running condition the way I braught it in. Now they sey they can't do that the vehicle wont be in running condition unless I get the other part fixed. My issue is after they did a full inspection before in August nd replaced my clutch kit as it was the problem how is it something else 3 months later! How do I know the mechanic did a propper job the 1st time? Everytime I call the service center for the manager he's on leave!