Cheap material

Good day

I bought a pair of shoes at identity wonderpark pretoria on the 1st of october 2016 wore those shoes on the 2nd and on the 3rd I realised that the material on the heel was ruined, I went to the store and I was advised that my shoes will be taken to their quality assurance department. Later that week I went back to the store and was told that it was my fault the shoes we're that way and I asked how because I didn't go mountain climbing but to an event that was held at venue that had pavement all over then I said to them I wanted to talk to the person who did the assessment on my shoes and I was told the whole department where in a meeting and I must come back monday the 11th of october 2016 that monday I decided to call the department and was told by a very rude customer care agent that which part didnt I understand that it was my fault. I dont understand how a pair of R500 shoes will get damaged overnight what kind of material are they using for their shoes as we speak my shoes are still at the store 1year 5 months later.