Bad treatment

I had a very bad experience at the Fix in Century city cape town.I bought a shoe there size 4 which is my size.when I got home the shoe was too small.I went to N1 city to exchange it for another size which is size 6,the following day I wore it at work but I realised its too big for me.I took it back again to Century city spoke to a lady that I believe she is the store manager there.,she gave me a very bad attitude and she did not even want me to explain my story.and according to my knowledge as a consumer you have a right to take an item back if you not happy about it as long as its within 30days and you have proof of purchase.I always buy things at the Fix but after the experience I had today I do not think I will.ever buy there again.