Technically, if all we are going by is federal law, you can accept the medication back, but you can't redispense it, and you'll have to destory the medication (per the FD&C Act). You should follow your company policy (and applicable state laws) on whether or not to accept the medication and provide a refund at a loss to the pharmacy in order to satisfy the customer. If this is an on-going issue, maybe create some prominent signage stating all sales are final and no returns are accepted under any circumstances, and have some process in which you confirm that customers acknowledge the policy before purchasing the medication?
Personally I don't deal with the problem of expecting refunds because none of my patients pay for their medications. Although some patients still insist on returning unused medications to us, and we repeatedly have to explain that we can't redispense the medications, and we don't dispose of unused meds, so we can't take the meds from them. Some folks will get upset with us for not taking their unused meds. Sometimes the situation is a family member has passed away and the caregiver is trying to make sure unused meds go towards good use (such as unexpired meds with the bottle seal still intact), or they just don't know how to best deal with safely disposing the medications. You never know what someone is going through or why they are so upset about something like trying to get rid of medications. I honestly wish we had a better system to support folks trying to get rid of unused medications. Sure, there are things like drug take-backs, but they aren't usually very convenient.
