Flipkart — Delay in delivery and unethical behaviour

I've ordered a Pre-paid motorola mobile from flipkart. It was supposed to be delivered on 9th Aug.

The delivery guy came on 10th; tried and wasted 1.5 hrs but could not exchange the old phone as he didn't know the process.

He said he would come back with another expert person on the same day but didn't come. Didn't pick up call and cut the call for 6-7 times.

The product showed 'out for delivery' on 11th but same thing happened again. Nobody picked up the call while calling delivery boy.

Flipkart helpline is saying they don't have any delivery manager's number to help.

It's complete harrassment as I'd need to be out of state tomorrow and my current phone is dead. Please help to resolve.