Usually, ranks can take a while to register to the user (It can be up to 1 minute, or maybe even 48 hours.) If your brother properly purchased a rank from this Network's store and hasn't received after 48 hours, I highly advise you to contact [email protected] via. Email with clear evidence of the transactions made.
The contents on the store of this Network are not refundable, therefore you cannot refund the rank.
If I didn't help, feel free to contact me or another member of staff on the forums, thank you. Thread locked as a solution has been given to solve the issue stated.