So I accidentally purchased DLC for the game "Hustle Kings" but I bought the PS Vita DLC and I have the PS3 version ! What can I do to get my account credited !
Not very much I'm afraid.
All sales from the PlayStation Store are considered by Sony as final & generally no refunds are given.
You could try contacting customer support to see if you get a sympathetic person on the other end, but even if you do don't hold your breath on the refund.
Customer Service - 1-800-345-SONY (7669)
Account & billing Support -1-877-971-SONY (7669)
Available Mon to Fri 8am - 8pm PST