Someone pointed out this thread on Reddit: Invoice Scam : newzealand (reddit.com)

Just to be clear: we do not send PDF invoices for our subscriptions. PayPal does the processing and charges the subscriptions automatically via credit cards. If a charge fails, there's no PDF invoice sent.

We also don't receive credit card numbers. PayPal only sends a notification to our server with the transaction number and if it was ok or not.

If you receive an email claiming to be from Geekzone but not coming from our domain then just delete it.