Bad customer service

I have bought oil moisturiser at Cosmetic Connection in George,the Sof&free avo&honey,on Friday.I have lost the receipt unfortunately,but I did swipe and the proof was on my bank statement,not the description of the item,but the amount.Today,Monday,I took the moisturiser back,because it was watery,and took another one from the shelf,so that the cashier can compare it,and agree about the consistency.She called her supervisor,who also agree that the consistency was watery,but she did not want to exchange it.I have asked her what her name is,because her reasoning does not make sense to me.She refused to give her name as well,and just walked away.Totally unacceptable,because I was not rude,I merely asked why it cannot be taken back,and the store can write it off,I have also worked at a retailer before,so I know about the policies when it comes to writing off products,but she just refuse.Now I have to part with almost R50,which in this economy is a lot.I am very disappointed in how she managed my complaint