I brought a white silk top to a cleaners near my area (VIP Tailors near Christie Pits) and when i got it back it was yellowy brown, stained the colour of sweat (when I brought it in there were a few spots but overall looked white and fresh as it was quite new). I was really upset and ended up bringing it to Golden Hangers in a last ditch attempt. They said they couldn't promise anything but would do their best. Next day I arrived and its as good as new!!! I was ecstatic.
Not the cheapest but DEFINITELY worth it for items you care about.