Checking ACH return/chargeback codes

[AnDaBl02]

I am using AIM to test ACH payment or refund.  How do I automate the process to check the ACH return or chargeback codes?  I have used a test account to submit refund.  I logged into the test account and checked the Transaction Search Results; but I couldn't see any return or chargeback code for the ACH transaction.

I also checked the Transaction Details API(GetTransactionDetailsResponse) but I didn't find the return / chargeback code any where.  What am I missing?   Is there a way to automate the process? 

[AnDaBl02]

or if I have to check the ACH return/chargeback code manually, how and where do I check it for a particular transaction?