What a day! The money I had been trying to transfer to the business partner finally reached the destination.
I figured that the only way to fish information out of the bank was to send a handsome male colleague to a female clerk. That what I did. The clerk was so impressed by my colleague's charm that incidently remembered how to transfer the money. The method was cazy, but it worked.
Hope, our business partner is not very disappointed and will keep on collaborating.