Playstation code problem?

I have 2 users on my ps4, one for me, one for my brother. Back on ps3, he had minecraft purchased on his account. On his ps store minecraft comes up as 5 dollars, on my store its 20. Before knowing this, i thought it was 5 on both, so i had gotten a 10 dollar card and put it on my account, and when i tried to get minecraft it said 20 dollars, and current balance was 10. On my brothers, minecraft was 5 dollars and balance was 0. Is there any way i can refund the code and enter it again on my bros account or can i transfer the balance to his store somehow?