If you cannot play the game due to region lock, please immediately request a refund. Please inform other people who quit the game and are in a region lock country to request a refund.
(Edit to note: I wrote this before seeing what at least appears to be confirmation that it was Sony who instituted the block, though it was just a support agent who said it and we know that always get everything right and have all the info available to their company...)
I'm pretty sure it's Valve that added the block to keep from getting am even bigger wave of legitimate refund demands and I wouldn't be a bit surprised if they're not reverting it until Sony gives them the actual plan and commitment they'll not try this stunt again.
Doesn't make it any less shitty, but I honestly couldn't blame Valve if that's exactly what they're doing.