Good but sometimes bad. Review on Flipkart

I am using flipkart from 4 years and all over experience is good and I worked with flipkart as well as a seller. Flipkart is very good is easy site to shop or buy products online but sometimes not because many times flipkart gave me defective products again and again just 4 monts ago I brought a mobile from flipkart but I got a defective piece than I give request to flipkart for replacing and they accepted that and after replacement again I got a defective piece and this happens again and again for 3 replacements after 3 replacement I got a perfect new mobile but it takes almost 40 days total. I know sometimes this happen but my issue is only this that they didnot gave me a refund and other sites give you the option is that you want a replacement or refund.and 1 of the best part of flipkart is 30 days replacement warranty no other giving you this service right now. So, use flipkart good site for online shopping