I Wang my money back or take something diferent

Hello I have bought 2 pairs of lacoste shoes orange one and Blue i wear them not everyday cause l line sneakers so much to my suprices ahora starded to Chang colour and ton i wena back to the shops i spoked to one Lady promise to assits cause she can ser that theme i its problem with the shoes i bought shoes costR1500.each.pair the mánager told me its my problem the is nothing they can do for me cz the problem its with my foot not there shoes its not for the first time i bought shoes from this shop cause i know it will Last me and im so dissapionted about this how can u pay shoes for R1500 and got damage before even 2months and the fact that im not wearing theme everyday it males me sicks