inconsistance policy practise and interpretation

Please be aware that I logged a complain at the store as they refused to do an exchange for me. In their policy it is specifically says we will gladly exchange your item at the current price. at my visit I did not get any joy and I left the Bag at Tygervalley store. My frustration is that, I had to wait for 30 min for the manager to make a decision regarding my visit of which at the end she said she will not exchange for me. As I was waiting for the manager, other customers were assisted with exchange. I felt discriminated, undermined and humiliated. I called on 2019/02/28 given Ref# ********** 8- ********** 82, no response till to date