To get a refund from Google Play you should first go here: https://play.google.com/store/account
Scroll down and you should see your purchase history. Each item has a disclosure button next to it, click on that and choose "report a problem". On the form that appears you can ask for a refund from Google.
If that does not work, we can issue you a direct refund. We’ll need your order number to complete the process, to find out more about your order history/numbers, check out this Google help page:
Please allow up to 4 business days for your refunds to be processed.