Swiggy — Refund for aswin samp

While ordering biryani from a restaurant, in payment page it showed save your card details, then I clicked it after 5 sec of processing then the same payment page came then I executed my order with only one OTP. then while receiving my order the delivery executive bought me two same parcel from same restaurant, only then I came to know that I placed two order one which I ordered with offers applied and the other which was executed without offer and without OTP. it was there app mistake if order is placed it should have shown me..but once again showed me the same payment page..then how will I know about order position..then I raised the issue with swiggy..they said refund amount is iniated..will credit within 7 days..but this is 10 days..now they are asking for bank statement..i already explained them and they told that they have initiated refund but suddenly.. behaviour like this..so kindly take this issue seriously..it's all hard earned money..hope I get a help