'Professional' typist in Chiang Mai?

I had a friend translate a 25 page document into Thai but he has no computer skills so he wrote it out by hand. I then paid a friend's partner who is a school teacher to type it up for me. However, it turns out she did careless work. My original translator friend thinks it would be easier to find someone competent to do it from scratch rather than trying to correct it.

I suppose I could hunt around various classifieds but I think my chances are better if I go on a recommendation from someone who has previously had good work done.