Order cancelled

On the morning of August 12 I placed an order for 4 tires. 5 minutes later I opened a ticket to cancel the order since I devices instead to buy tires local at a ship near me. Once they responded to my cancellation they told me that they have sent the cancellation request to the warehouse. Later that evening (about 10 hours later) I received an email that my shipment was on the way. I was told by them to just cancel or reject the shipment. So that's what I did the next day. It's now been a week and they have not refunded me. They are unhelpful to me. They won't tell me anything about my return or my refund.