The only way a machine shop will know if the crank is balanced correctly is to set everything up in the balancer and give it a spin (that is the hard, time consuming part of a balance job, drilling a tad more or a couple spot welds takes very little time), if your machine shop did all that and could not spend a few minutes more to correct the balance issue I would be looking for a new machine shop. I had a used rotating assembly checked to see if it was internal or external balance (and done correctly the first time), the guy I bought it from was not sure, they knocked $10 off a normal balance job and said it was because they still had to do the same set up and checking everything. Am I crazy or missing something?