Sorry to hear your still having problems. I've been on the game myself today with others. So it may be an isolated issue.
As for a refund. If you purchased the game from the PlayStation Store. Then you'll need to give Customer Service for your country a call. You'll need the order information from the email you get when making purchases. If you bought it somewhere else. Then return it with receipt. Should be covered by 30 day guarantee that most places do.