You mentioned the "fit" was done by your LBS, but it isn't clear what the extent of that fitting process was. If all they did was have you stand over the bike to see if it was the right size, go someplace else that specializes in thorough fitting services and pay them for that work. If it was a thorough and elaborate fitting process you got from the LBS, go back and give them a chance to sort it out for you. Good shops who claim to be fitting experts understand that it's seldom a one-shot, you're-done-and-out-the-door solution. They know that the whole process needs time dial in just the right setup. They should not be surprised to see you again, nor should they balk at working with you further.

Whichever route you take, make sure you're perfectly frank with them about the nature of your problem. They need detailed information in order to help you.