Domino's Pizza — Refund not provided yet

Address:	Gurgaon, Haryana, 122016
Website:	Www.dominos.co.in

Outlet: Sector 22, Gurgaon
Mode: Delivery to home
Date: 28 Aug 2016
Bill Amount: 912
Very simple, straightforward case.
Got my pizza late after waiting 30-40 mins. Had already done online payment. Delivery boy said he would inform the store and refund would be initiated.
Till now I have followed up by calling the store more than 5 times but they say they don't have time.
Update: Store manager just told me that since the order is was like a month ago, I won't get a refund.
I need resolution immediately.