Online Rims Simulator!

help, last friday i feel that my car air con is not cold, so sat i send to the workshop for inspection. then the mech say its because the air con gas not enough, so he just refill the gas for me and say ok d. then on the way i driving home, i can feel the cold air, but then got some gas smell when the moment i just on the air on. then today when i drive the car again, the air is no more cold liao.
i was wonder i can smell the air con gas inside the car, mean there is some leakage right?and...