What would you do in this case?

My husband was placed on high blood pressure medicine two months ago and when we got his prescription filled for the second time the local CVS store mixed in a pill that did not belong... I looked up the medicine and it is Alprazolam (used for anxiety & panic disorder) I did a drug interaction with this pill and my husband other medication and I found out that if he had swallowed the wrong pill that day it could of had a bad reaction with four of his other medicines, and a food interaction if he had drank any grapefruit orange or apple juice on that day.

So my question is -
Should I contact a lawyer over this matter or just let it go, or talk to the legal department of CVS and see what they have to say?

Thanks.