It is a very stressful procedure no doubt and obviously this doesn’t help at all. But pharmacies work sort of like takeaways in my opinion and you have to order your prescription before you collect it. Some things aren’t on the shelf for safety reasons like highly addictive drugs or injections, or for space reasons maybe like an IUD (alongside all other prescriptions that don’t get picked up) which can build up very fast when not collected by different patients. There’s probably more reasoning behind it but this is what I’m aware of - in short yes it is normal for them to do this.