Keep on them, because it may take a couple phone calls. When you talk to them, write down who you talked to, when you called, and when they will call you back, etc. If they do not call you back by the time agreed upon, call them back with this info...and go from there. If you track this, you should get much quicker help because you can cite specific dates, names, etc.
It may help to talk to your primary doc who first brought up the benzo concern, and see if they can write a quick note in support of this, so if it comes up during your phone conversation you can tell them your doctor advised you about them, etc.
-pedagogue