Frustrated customer

I am highly annoyed and irritated.I bought shoes at Fashion express on the 20th of December 2015. And as it is the entire heel of the shoe is loose and about to break off. Its hardly a month and i have only wore the shoes 3 times. What irritates me further is that i bought them cash an i am no longer in posession of the proof of purchase, which means my shoes will not be refunded. I spent close to R300 on these shoes. I am no longer buying anything from them as they dont sell quality material.