Hi Chelidio
I'm not sure if you are you saying that
in total you didn't spend more than 4 months there or that
each stay was less than 4 months?
I suspect if you accumulated more than 6 months there in a short period of time CIC will probably require the CHIR (eg 3 months there, 1 month out, 2 months there, a few weeks out, 3 months there etc.)
If you're doing an out-land application perhaps you can call the consulate that will be processing your file and ask them to confirm it for you? I've found speaking with the consulate directly to be much more helpful than calling CIC.
If you do need the CHIR and the consulate in Turkey is not being helpful, I would suggest having a look at the website for the South Korea National Police Agency here
http://www.npa.go.kr/main/index.do. I can't find an English version but if your wife has been working there perhaps this is not a problem? I assume they are the ones would actually supply the certificate so maybe there is information somewhere on this page that might help you - or perhaps another member of this forum will know.
Sorry I can't be of more help.