You are likely out of luck. "We will process your refund request as quickly as possible, but it could take up to 72 hours for us to verify your claim. If you have started downloading the game to your console, your request will be declined and we will notify you of this."
It doesn't hurt to call, however be aware Sony are within their rights to refuse a refund.
Number is at the bottom at they open...now at 10.30
https://www.playstation.com/en-gb/get-help/contact-us/