Croma — Refund not credited

I ordered a oppo A16k phone from croma on exchange offer for Rs 9990 but the delivery person didn't take the old phone as it was cracked and I had made online payment at the time of placing order .i was promised a refund within 14 days but now it is a month and I made 10 calls 6 complains( registered) and still haven't credited with the refund ! The credit card bill is on my table i m supposed to pay it but why should I if I haven't even spend it ..it's cromas responsibility totally for the situation I am in i want my money back as soon as possible or will be forced to sue you croma!! Order I'd :[protected]
Sanjay Pandey