Walgreens

I take truelance daley, it is on auto refill and my insurance pays for it. Every month I run out due to walgreens not having it in stock, walgreens knows ill be needing it every month at a cretin time and its paid for ny bcbst so why cant it be ordered in advanced so I dont run out every month? I need this medication in order to digest my food and when I start skipping doses it causes big problems and some times it takes a week or more for me to get regular. I have contacted walgreens directly and there reply is more medication has been ordered