Purchased an item, still haven't recieved it, what can I do or say to them legally?

I bought a case 4 weeks ago for the iPhone 6, when I bought it it said 1-3 day delivery, but that never happened. Long story short after countless unanswered emails over the spam of 3 weeks I decided to cancel it. But the cancellation never went through and another week went by. Now it's the fourth week. I emailed them asking for the manager's email and for my refund, that same day I got a shipping label, but the item was never shipped. They've charged me even though I'm not receiving anything. I'm done with them, I'm done with this whole ordeal, what can I do to get my money back??? Thank you!!!