I started using amazon two years bank, from then then I never got any issue with the customer service.amazon have best customer service which gives service for 24*7.the products which are sold on amazon are 100% genuine and original.the product you get are of good quality.talking about delivery time if you are prime member and living in popular cities you may get your order delivered in lesser than six hours.the delivery time varies from 6 hrs to 7 days depending upon the area you ordered the product.it deffinetely arrives on or before the deliver date given by he website.you can use amazon either via web or via app.the app is highly reliable and useful.