I WANT MY REFUND

I made a payment on the 2nd October 2018 then I noticed that one of the items in my order was cancelled, I sent them an email then they advised me the item was out of stock and I must send my banking details for refund. I sent my banking details but they didn't reply. I have been asking them how long must I wait for refund but no one rep****. Their service is pathetic, I want my money.