What are my rights as a customer?

What an experience this was, so I bought a shoe at shoe city, wore it and then found out that the right shoe has some problems

It was going to the side when I walk, anyway I went to the shop, at first the lady I found there was willing to exchange the shoe for me

Then came a different lady who said the shoe could not be exchanged because I had worn the shoe, I asked whats the purpose of the shoe since it had to be worn… like. Anyway she continued to tell me that she won’t take the shoe.

I called shoe city customer services about 3 to 4 times after deciding I should email them, after a few days a guy named Elias called me , he said hes in Johannesburg and couldn’t come to secunda to sort out the matter, he tells me that I must go back to the shop and model/parade the shoe so that the lady can see whats wrong with the shoe because she didn’t know what to check for the first time I went there. Im disappointed by the customer service there really I mean, how am I expected to go back to the shop after going the first time to model a shoe. To a person that told me that shes use to people coming here looking for exchanges after they had gone to the event and are done with the shoe. As a customer is it even right that I have to stuggle this much for an exchange not even a refund…