Never take a dog to the groomers with tangles in the hair unless you want a shaved dog. It is difficult to get any groomer not to shave a long haired dog as it is. Groomers are so accustomed to having people come in with matted dogs that the owner wants groomed that pretty much all they do is bathe and shave. There are few that actually know how to trim up a long haired dog.
There has been many a sad Yorkie owner posting on here because they took their lovely fluffy pup to the groomer and picked up a naked dog! Sadly, not many groomers are trained in how to bathe and NOT shave but just do enough snipping to make a pup look neat and well groomed again. It takes a bit of skill to tidy up a long haired dog but anyone can shave all the hair off one.