On the exchanger website, in the rules that you agreed to when creating an order, and on the order page, there is a warning that you should not split the deposit into several parts, screenshots:
https://bc.to/hN0SQM,
https://bc.to/oxDQBU.
Also, according to the exchanger's rules, the user undertakes, if necessary, to provide verification information to the exchanger, screenshot:
https://bc.to/rcFXk0He explicitly claims that there was only one order - one transaction, and he did it several times, and that there were no splits into multiple parts. It sounds like someone isn't telling the truth.
Did you even ask for any evidence from the exchangers and user brett6934 to establish the facts? I assume that you do not represent the interests of your partner without checking on your part.