Very bad service

I bought the Spitz shoes on the 15 Sep 2018, when I got in the shop I asked the sales person to give me size 7 which did not fit me, they then brought size 8 which was big, The sales person then gave me size 7 & half which was still small. I was told to wear the shoes as they will stretch. I then paid for the shoes believing what I was told, to my surprise when I got home the shoes have even caused corns on my feet. My feet were swollen. I then took the shoes back which I was told they will not take them back nor refund me. When I told them thus not what I was told when I bought the shoes as the sales person was interested in selling the shoes at my cost. The store Manager Mandla, took the shoes and promised to stretch them further when I asked wouldn't that compromise the quality of the shoes, he said thus what they always do when shoes don't fit their customers. I gave him another benefit of the doubt as they stretched the shoes for a week, he then brought the shoes to my home which still did not fit me. When I told showed him that they don't fit me, he promised to speak to his bosses which to date I have not heard anything from him. I am now remaining with the shoes that do not fit me and I have lost R1700. I am not working took me 24 months to save the money I am getting from selling funeral policy. This is Spitz in Polokwane and I can't believe my dream has turned into a nightmare.

Can someone help me as I don't know what to do. Spitz employees are only interested in meeting their sales targets without considering customers' health and needs.