Finding missing super payments that were processed through MYOB Pay Super

I was advised by an employee that they have not received some of their super payments. When I investigated what had happened their member number was correct but somehow the fund had changed to a different fund which was not their fund. I corrected the error and went back to look at how many super payments were incorrectly transferred. I got in touch with the super fund that had received the super payments and they said that had refunded one payment but never received the others. They told me to contact MYOB if we hadn't received any returned funds. Who do I speak to at MYOB about chasing up the missing funds that in my pay super area it says 'completed' and the money was taken out of our bank account but is now missing somewhere as it was never received by the fund that it was allocated to (except one transfer they they say they returned but is also missing)