ShopClues.com — Supplied defective product

I purchase one remote car from shopclues.com against order no. 58088049 and when i found that product i was shocked that it was defective from the starting. i registered a complaint no.3385170 on 9th. July over phone and i was informed that in next 48 hours it will be replaced. Nothing happened till now. i called many time now they are disconnecting my call. i mail them many time and fulfill their requirement my sending photos of bill and product. now they are saying they can not take the product back because they do not have reverse pick system and i have to pay courier charges which will be around 400/- against purchase cost of product rs.470 please help me to get back my amount and do something for other also so that they can not cheat others.