Prescription medication - Consumer Complaint for Clicks Store - Head Office

Hi. My husband Johan had a heart bypass surgery and collects his monthly prescription medication from clicks pharmacy in winkelspruit. A few days ago he went in to fetch it and as usual it was all sealed in a bag. A day later when he opened the bag he discovered that one of the main medication ( plagrol) was not packed. He went to the store and was told that it was packed. He then had to buy another bottle and pay cash. I'm very confused. I know one should check their medication but he obviously trusts that all is 100% or they( clicks) would have told him if they didn't have stock. My question, What happened to that bottle of medication??? Would it not reflect as one extra on the system or did it just vanish? Trust is very important when it comes to medication and pharmacy.
I would like some feedback please. Thanks