Decathlon — Didn't recieve refund and new order

I returned a product and I didn't recieve the refund. I ordered a new product which was prepaid and I didn't recieve the new product as well. I mailed to them twice still the issue didn't get resolved. I tried to call the customer care service but the call wasn't answered.
I didn't recieve the refund and the new product.
Kindly look into this matter.