Adidas — Complaint about refundable amount

Firstly I bought adidas x speedflow turf boots from adidas website using cash on delivery mode, I took the product and there was problem with the size so i returned the product the very next day. I recieved a mail about my returned product so tracked and did the so instructions provided. They stated it will take around 14 days to get the amount back so i waited but Its been nearly a month and they still haven't returned my refundable amount back.
I tried reaching out the customer care service through call and mail but there were no response to it.
My order no- AIN00718649
Please look onto the matter and resolve it.
Thankyou