Phone is not delivery

on the 16 of march i have received my contract phone with wrong color. I called cell c to collect it and send the correct color. carrier collected the device on the same day (16 march) . Today i called need to know when they deliver a new phone. cell c contact centre agent told me they haven't received the phone. why it takes so long to because i have use the phone? . the services or the process cell c use is ridiculous .14 workings days to get your a new phone when you return unused phone. now its gonna be more days because carrier company didn't deliver on time. please help to get my new phone delivered this weekend