****** and rude

Bought a baby sense carrier on the 26th of june but when I got home I realized that my baby is too small for the carrier even though it says its for babies from newborn.I decided I was gonna take it back but my baby fell sick and I spent the entire week in hospital,on sat the 4th I decided to take it back as it was still under 14 days and I wanted a refund as I hadn't planned on buying anything. Got to the store,spoke to the guard and he refered me to mitchell who is apparently the assistant manager. I told her I wanted a refund as it felt like my baby was suffocating in the carrier and I was not satisfied with it,she told me that baby stuff can't be refunded or exchanged,I asked her how so when they only sell baby stuff and the slip says refunds/exchanges are accepted within 14 days,that's when she said she will only exchange it but can't give me a refund and that I should choose what I want. She was so rude and looked at me like I was crazy,I had to buy something and pay money I didn't even plan to pay,all because to her I'm stupid and don't know what a hygiene senstive item is.