premise: Then I went to Walmart to pick up 4 RX refills I called in yesterday . They had 3 but the doctor who prescribed my Lisinopril for high blood pressure is the one we just dropped and he did n't call them back . They loaned me 4 from my next prescription so I have about a week 's worth left . Why did n't the doctor call back ?
hypothesis: The doctor was too sick to call .