What payment method did you use?
I suggest to contact your bank or credit card service and request a dispute form. Also note that you have attempted to contact the retailer without avail.
Possibly there's no reason to freak out, but usually banks/ccs have a 31-45 day term wherin you need to declare a disputed transaction or they won't take action (anymore).
If you do call in the dispute also inform the company that you have or that you will.