Hmmm ... I'll have to go do a fresh test to confirm what it should look like.
Depending how you integrate it, I'd suggest that you remove the random letters and use the external order generator ID you were using.
I'm not sure how that exactly corresponds correctly with a Zen Cart order record, but I gather your client has already figured that part out.
It's up to you which method you choose. Some like to have the convenience of doing a refund directly from the order page in their Zen Cart admin instead of having to login to the authnet console to do it.
Lotsa fun when the client freaks over things when something changes on them.




