sold me shoes with factory fault!!!!

I bought a pr of high heeled shoes from ALDO on the 27th Nov only to discover when I wear them that they have a factory fault - stitching at the back is not aligned with the heel. Upon returning the shoes, I was told that the OPS manager will look at it and decide...what a lot of BS!!! Got a message later in the day that \there is nothinh that can be done about the shoe because I had worn it". How else was I supposed to find out about whether the factory fault will hurt my feet or not"