false advertising

have just ordered my first pair today tried them on way too small and i went according to their size chart I sent a email immediately for a bigger size which she sent me the link for exchange now the scary thing is when i put in my order no for the exchange it says order no not found????? i have all their previous emails with order no clearly stated have sent emails and now silence I will not be conned into this their website says hassle free exchange and it is the same day i received them I will do anything in my power to tell people to stay away also the shoes which cost R1400 look like they might last 2 months poorly made. I was so hoping it would help with my feet problems I just wanna cry