... the product is defective, please notify us within 3 days of delivery.3). All products must be returned on their ... .4). Buyer is responsible for shipping cost of returning, seller is responsible for shipping cost of resending. Contact us:Shenzhen kangshengda tech co. ... T, 808D, 801, 901, cigar, pipe etc and all kinds of accessories, such as atomizer, cartomizer, battery,cartridge, charger. How to ...