I am from India. I bought a 700W hair brush today but it doesn't seem to be working. There appears to be no power supply at all. Is it the fault of the device? Or is there a fault in the electric current supply? What should I do?

It is probably the power supply.

Try plugging some other electric device into the power outlet. If the other device works, the power outlet works and the problem is with the hair appliance. Or try plugging the hair appliance into an electrical outlet somewhere in the house and see if it works. Is this question for real? Not trying to be rude but it doesn't seem to make too much sense...

@clairermsmith. He is in India, yes it does make sense.

1. Defective
2. You instantly blew a fuse/circuit because of the high wattage
3. Is it rated for India's requirements?
Read this:
Electricity Around the World