Besides, as a newbie, no matter how many merits he has, he is limited to 2 PMs/day, with a limit of 1/h. So he can send only 2 PMs in a day. Maybe it would be more helpful to him to try the following:
- raise the issue in the board above mentioned
- state the issue by hinself instead of you. Maybe there are users knowing the guy who received the funds by error and maybe they convince him to return them.
- buy a copper membership, which would grant him the privileges of a Member, although he would still be a newbie (from here: https://bitcointalk.org/index.php?action=credit;promote). This membership would allow him to send more PMs (details here: https://bitcointalksearch.org/topic/new-pm-limits-2536728).
- another way, in order to avoid paying the tax for copper membership, would be to kindly ask theymos or other high ranked staff (Cyrus, for example), to whitelist his accout (details are also in the last mentioned link).
- finally, the user receiving OP's PMs should have activated the option to receive PMs from newbies. By default, this option is set to OFF, so no matter if IndecentProposal can send him 100 PMs or 0, the user who received the funds by mistake may not see even 1 PM from OP if he didn't change the setting regarding receiving PMs from newbies.
Besides all of the above, I'm asking again, why doesn't OP try to discuss here instead of you?
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
Anyway, I hope the above suggestions will help him.