You also have to check and make sure there is not some supply distribution problem up the chain....

For example oxycodone IR has been short nationally for quite a while. This varies from area to area.

http://www.ashp.org/drugshortages/current/

The FDA site is currently listing methylphenidate as well:
http://www.fda.gov/drugs/drugsafety/.../ucm050792.htm

Controlled substances are given a quota yearly to each company. If they run out of raw material, they have to wait for the next round.

Also some companies run into snags of their own, and may stop shipments. This happened to Glumetza last August...It just became available again in Feb 2011 as an example. Same with Merck and the infamous Sinemet shortage (which was global).
Fentanyl patches are always being recalled for various reasons of defect. You can call the companies up yourself to double check what Walgreen's says.
For example CVS still does not have Glumetza, but Walgreen's did and so did Medco. CVS says they cannot get it.
Makes one wonder doesn't it?

So check and make sure your medications not on these lists, before you complain further.