Question About Medication

[blageo23]

So I went to walgreens the other day to buy some sudafed. You have to pick it up at the pharmacy. So I went there and they carded me, no big deal. the dude said I couldnt buy it because I was "over my limit" and he could not sell me the drug. Problem is I have not bought that drug or any other in at least 3 month when I bought some allergy stuff. Does anyone know what they go by when checking the ID? Is it your name, address or DL number?