I bought a pair of Saint Laurent shoes for my wife that unfortunately were a little too large. She tried them
On once on her birthday. I returned them for an exchange. Net-a-porter, albeit within the return period, let me know that after inspecting the item they would not accept the return claiming the shoes had been used. It's hard buying shoes without the ability to exchange them for ones a size smaller or larger. I cannot recommend buying expensive designer shoes with net-a-porter and won't do so again myself.
Update: After writing this review net-a-porter exchanged the shoes for the smaller size - now they are a fit.