Entirely Pets - Online Pet Supplies Charged card after order was canceled. No refund given. Internet

I placed a large order with Entirely Pets on December 11 2014. On December 16 I had heard nothing and my order still stated PENDING on their website. I emailed asking when my order would ship. I received a reply stating my order was processed and would ship December 17. On the evening of December 17, order still showed pending on the website so I called. I was told the order had not shipped. I requested that the order be canceled during that call, and also replied to the email I had received, also asking for the order to be canceled. The website updated within minutes to show that the order had, indeed, been canceled. On December 18 I noticed that my card had been charged for the order several hours AFTER the cancel request went through and the website updated. I called Entirely Pets and was told I would receive a refund in 4 business days, up to 2 weeks.
On December 21, I received another email from Entirely Pets stating that my order could not be canceled because it had SHIPPED! I called immediately and was told it had not shipped and that the company had issued "store credit" instead of refunding my money as I asked. Store credit does not appear anywhere in my account on their website. I re-iterated that I insist on a refund as I will never do business with this company again. I was told my refund will post to my account in 4 to 6 business days.
I find this completely unacceptable. They canceled the order BEFORE charging my card. The order has not shipped. I do not want, need, or in any way plan to use any form of credit with this company. I demand am immediate full refund credited to my card.