Cheap goods at exorbitant prices

I purchased a nude pump (shoe) from Woolworths Vincent Mall EL in June 2015.I somehow managed to lose the slip but the woolworths logo was inside the shoe to verify my purchase.After wearing the shoe for just over a month,I noticed the leather wearing on the shoe and referred the complaint to the customer centre in Durban.The feedback and service I received was appalling to say the least.I was told that the shoe displayed normal wear and tear and the agent reporting back was rude.I would like to ask dear woolworths why they import cheap goods and sell their goods at such exorbitant prices.The price of the shoe (genuine leather uppers) was 400 rand and I don't get their rationale of wear and tear afterjust one month of use?what method are they using to test wear and tear,surely it it not a reputable method? After investing so much in purchases from this company, I am quite perturbed.I am closely guarded when making a purchase from woolworths again!