Hi, I preordered a PS Vita and registered the preorder code it came with it and I gave me an option to get a discount for game so I chose Star Dust Delta.
The annoying thing was I thought it was put into effect immediately and I bought the game immeadiately and a day later I get the discount voucher code which is total BS.
Is there a way to claim the discount into my wallet on PSN or change the discount to be towards another game?
I hate to say it but in this situation, you're out of luck. PS don't do refunds for accidental purcahses and the site where you redeem your codes does state you will be sent a code to enter to activate the discount in the store. From memory it also asks you to choose carefully as the discount code will only work for that one game and cant be transferred.
TL;DR - No.
You should really read the website when you redeemed the promotion. As SonicHedgie said you'll have to just suck it up. The promotion code that you have now receievd should be used for another one of the selected games which means you still are entitled to your discount but you've just purchased an extra game at full price on your accord.
"From memory it also asks you to choose carefully as the discount code will only work for that one game and cant be transferred."
Unfortunately it does advise when you are choosing the game, that you will receive a code to use, and once the game is chosen, it cannot be changed.
Perhaps offer the discount to a friend instead?