For me, they only gave me enough for 2-3 weeks.  I'm on a different insurance plan, but I found out that it wasn't my insurance.  The company that makes Lamictal is doing end of year whatever-it-is that makes them restrict the lamictal.  Nice, huh?  My pharmacy has more than a month's worth of Lamictal (I'm on Lamictal XR) so this doesn't happen to me again. 

If it IS your insurance company, you need to contact them and see what the problem is.  If there are still issues that you cannot resolve, have your dr. fax a claim/notice that it is imperative that they supply you with the correct amount of pills to last you a month.  This is non-negotiable.  You need your medication and it shouldn't be decided by a health care company that doesn't know you or your epilepsy.   That's what I'd do, but others may have a different approach.  Get what you need!