Wrong Medication was given, which ends up being the customer’s fault

A few weeks back my mum went to Tathiti purchasing medication, she was given the wrong meds by a pharmacist, keep in mind my mum doesn’t have means of transport to go back and forth to the pharmacy. I went today to inform them about the mishap that occurred, the stuff was not bothered,I was told I need to go back and look for the till slip, when do people ever keep the slip after getting what they need? However I am looking for it. Anyway I was told even if I find the slip they cannot change it although it was a mistake on their side. My question is what if a pensioner gets their monthly meds and this happens? How do you expect them to pay again just because someone did not do their job correctly? I went to change it for the right medication and was told I cannot. So next time you plan on going to Tahiti Pharmacy in Lenasia, just know you might not get the meds you paying for and also you can’t change it, they would charge you again because of their mistake.