CASE are good, but there are more authorized service guys.
here's a link to the others
Apple - Authorized Service Provider Personally used Wah Fung as well as CASE, both are good.
If you don't want to repair with apple authorized resellers then you can try sham shui po 1/F Golden Computer Centre "6688 computer".
I had a similar problem to you and went to CASE service centre, they fixed my fan on my macbookpro, no problems since.