Disappointed by wrong/incorrect sneaker colour, company not reachable for an exchange

I ordered Samba sneakers, I was so happy to receive my order within a week. To my surprise and disappointment , the colour was wrong, they gave me Red instead of Green. Within a day I emailed them to inform about the colour mixup so we can schedule an exchange, but there was no response to this day, I visited their website and tried to contact them on the chatbox, asked me to leave my details so they can contact me, still no word from them, I tried to call but the number doesn't go through, their exchange policy is 7 days but they are not reachable. I'm frustrated and was inconvenienced as I needed to wear the Sneakers to some special occasion that has already passed, I couldn't because the colour was wrong. I hope they eventually contact me for an exchange, for the right colour. Otherwise what do I do with Red when I wanted Green? Disappointed