So you had access to the content, but got a refund. But then, trying to do the right thing and give them their money back, you get locked? That's not cool.
First thing I'd check is the activity history of your Paypal account. Perhaps you accidentally paid twice and they refunded the double payment?
If that wasn't the case, contact Paypal to try getting a reason for the refund and what you need to do to resend it. (Where are you located?)
Unfortunately, it's the weekend so the chance of any of the Powers dropping by before Monday is slim. Good luck, tho.