In test mode,When I try to make refund for my transactions via Authorize.net AIM by using only the last 4 digits of credit card , it shows the following error.
(TESTMODE) The credit card number is invalid
But strangely, when I enter the complete creditcard number(4007000000027) , the refund works perfectly fine ;
So how can I make my transactions refund by using only the last 4 digits of my credit card in test mode ?
PS: I even tried XXXXXXXX0027 as an input , but didnt work.