Faulty Aircon on Kia Picanto

The aircon on my Kia Picanto started making a noise.Kia Picanto South Africa authorised the agent in Herm**** to have it fixed.I accepted this kind offer.A new compressor had apparantly been fitted.After the Picanto had been returned to me I discovered that the the aircon lost its efficiency in that it did not cool down the car as previously.I returned the vehicle and is now beeing informed by the agent that it seems that the switch on the aircon is faulty and that Kia South Africa is not willing to make any further contributions and thus refuse to make good their promise.The agent said that I must now pay R980 to have a new switch fitted.Upon my enquiry as to what if the aircon is still faulty the agent representative said that they wil then just refit my old switch.This leaves me under the impression that the agent is still not sure whether or not the switch is the real problem .I had the car with them on three occassions and everytime its a different story.I feel that Kia South Africa committed itself to fix the problem and now that the going gets tough they shy away.