069 Error Code for Refund


My Moneris Gateway is working properly, but I am having an issue with processing a refund. I am getting an error response of 069 "DECLINED           * SYSTEM PROBLEM     =CANNOT PROCESS*PLEASE RETRY". The transaction amount is for $0.99 and the user paid using credit card vault. This is the only refund that is causing issues (other refunds have worked correctly). The refund process attempt shows up on my Moneris Gateway with the purchase.

Are there any possible causes for this error code I can look into?