Using PWCC balance/credit to pay for PWCC listing

[nocontest]

I just recently started using PWCC and from what I've read I should be able to use my PWCC balance as payment towards cards purchased from their auctions/vault. I can't seem to figure out how and I even had a chat with a rep earlier with no success.
I was told I should add the item to my cart using the BIN button, then leave checkout and head back to the PWCC website where an invoice should be generated. I do not see anything of the sort. My ebay account is also linked to PWCC.
Has anyone used PWCC balance to pay for listings? If so can you please help me figure out the process? Thanks!