I could see mainly wo issues,
They dont take ownership. Want us to contact their partner vendors for resolving the issues.
Their customer support does not seems to understand what you are writing. They just send their standard messages again and again.
Till now I have made 3 purchases. Two times the delivery was made in around a weeks time with out any defect. Once they messed up but gave full refund. I came to know recently of my colleague also who got full refund for the defective item and hence it is improving my confidence in rediff.
In case if you find the item to be defective, return it immediately. And interact with rediff support itself for resolution.
If you dont have tight timelines rediff is worh a try.
The site is fast and easy to use and the tracking gives you the shipping number also which is good.
Regards,
Bibu