yes better go directly to Denso if your car has aircond issue. recently only i kena from 1 workshop in Tmn Len Seng, Cheras and wasted rm1400+ for their so call expert service.
First went there cause my aircond is blowing hot air. they plug in the meter & told me that the gas was low. After topping up the gas they said the compressor is not working so good & recommend to change the
compressor together with the condenser as well. after the gas refilled the aircond is back to working condition and guess what happened after 2 weeks? strong gas smell inside the car cabin & aircond was blowing warm air. Brought my car back to the same workshop & they said the cooling coil was leaking & need changing. they also asked to change the compressor magnetic coil since they said the compressor is not working good.
ok, fine trusted them. guess what happened again after 1 month? the compressor finally worn out. brought car back to consult them why so fast the compressor spoilt after changing the magnetic coil and now they said it has nothing to do with the coil & said its the compressor inside component spoilt. i said you guys should told me earlier to change the whole unit compressor but instead assured me that changing the magnetic coil was enough.they don't want to take any responsibility and claimed what they did is correct.
so guys, long story but a lesson learnt with my hard earned money. watever it is, make sure you go back to your sc or direct to Denso for aircond issue. oh yes, 1 more need to add to this story of mine. before sent to that workshop the aircond blower ( inside cabin) was working good. after took my car from the workshop the sound from the aircond blower was like a fighter jet ready to take off. guess what they workshop said? boss, we did nothing, we only took it out blew the dust using the compressed air. same thing, they won't admit its their wrong. 
fyi, the location of the shop is facing the traffic light. next to them is a car spray paint shop. please pm if you need to know the exact shop name but its not too difficult to identify since only 1 row of old shop at Tmn Len Seng Cheras.