Return and Refund of my money

The company of Amazon didn’t return my money of a product which I first ordered and then I didn’t like it so I canceled it on 24 – 5. – 18 and 4-5-18 is present but I didn’t receive my refund. They always tell me that the money will be refunded in 3-4 business days when I contact with them. But the money was not returned in my bank account so please take the action towards this miss behavior