Missing huge sum of money sent via Trade Offer

Hi,

I sent $20,000 to another airlines using trade offer and the other airline only received $880 and I some how got $1100 back. I have no idea where the reamining $18000 went…we are both apart of the same corporation and he has 40% share. We tried it again and the result were the same…the receiver only got 0.044% of the sum that were sent. No goods were exchanged…any idea where the remaining sum of the offer balance went?