I need some help with Ola Electric Service

Guys, I need some help in filling an official complaint in the consumer’s court. I’ve ordered a set of break pads from ola electric store, and I have yet to receive it. It’s been 20 days since I placed the order. On calling the service centre, they have failed to provide any help. All they say is ‘Wait Karo’. On cancelling the order too they have refused to do that and have again given the same reply.
How do I file a complaint on them?