I've used Choiceful.com for a few years now, and there customer service is just superb. It is without doubt my favorite online shopping place, both because of good prices, but mainly cause if something is wrong with the product they just replace it, no bull, no nothing, and they even ship the replacement before they receive the old one back, so there is as little trouble as possible for the customer. Apart from offering some of the cheapest electrical products on the internet, they also offer a fantastic level of customer service.
If you are looking to buy from a reputable and leading online retailer, Choiceful.com is by far one of the best I have ever had the pleasure of using.