Car is about 14 years old but very sparsely driven. Recently serviced, turns out radiator was empty, and then radiator fluid was added. Later on a leak was detected in radiator fluid which was fixed. Now, after three months of usage, turns out the air conditioning gives out a very noxious smoke (transparent) and is literally unbreathable, and gives the car passengers wheezing cough.
What are we doing wrong? I'd really appreciate if some expert gives us some advice before we go clueless to the repairman and we don't want to be taken for a ride.