I had a strange experience several years ago with the William Blair International Growth Fund. I got a statement and found that $15K had been added to my fund. When I finally raised someone on the phone who had the authority to handle it--which required me calling a few times and nobody calling me back--they were quite nonchalant--oh, we already know about that. Well, when the hell were you going to tell ME? Although they promised to fix it, and did, there was no feedback--I had to keep calling them to figure out the status of the money. They also wanted to change my account number, which I refused to let them do. An honest mistake handled proactively would have been acceptable to me, but this was poorly handled. It was their lackadaisical attitude that really pissed me off. I was dealing with their transfer agent (State Street, I think) and could not raise anyone at William Blair itself on the phone. Could not even figure out how to contact them; all roads led to State Street. Ultimately I transferred the money elsewhere. There are too many good fund families who care about their customers and communicate well with them (and some of them are many times the size of Blair and have plenty more fish to fry).
TOS' failure to address this in a timely fashion is unconscionable. More bad customer service from huge firms. Your best chance of getting it expedited may be to embarrass them, i.e. go to the press. You should complain to FINRA, etc. as suggested above, but I doubt that it will move them any faster. Any firm that size could have numerous complaints that are active (many of which may be baseless).
Sorry for your trouble. Let us know how it turns out.