Snapmint — Need to cancel the order and need refund

My order id is 7516700
I ordered a MUFTI Plain Cotton Slim Fit Mens Casual Wear Shirt from snapmint based on emi. The down payment is ₹158 I paid. One day after order the product snapmint site shows it’s out of stock. I contact them but not responding. Didn’t get any response from their site. I need the refund and need to cancle the order .