7 day no return policy for a brand new travel set from baby city

Bought a travel set from baby city a stroller and car seat. Was told that baby can use from birth to Twelve months. My baby is going to be 1 month on the 8 October and car seat not fitting. We only opened the box today 6 October as we want to take baby out on the 8 to celebrate one month. Accorging to baby city in the crescent they cannot exchange as they have a seven day return policy. This item was purchased on the 24 August baby was born 8 September so this item was already not exchangeable. Please be careful of purchasing from baby city as I feel if the item was used and we trying to return then maybe I would understand but to pay R3000 for something we cannot use then this is not fair. As for the manager Vino totally not helpful. I know I will never shop at baby city again as service is extremely pathetic.