I think that without more specifics (eg retailer, special offer and whether any promo/discount codes were used) it’ll be difficult to answer that one. FWIW, the “on the way” email is a standard one that’s sent out after every purchase, and there’s probably a “credit is still subject to having met the T&Cs” in there somewhere.

Just out of curiosity, why was the missing credit taken up with the GGL line, rather than using the ‘proper’ function provided for this purpose in the e-store ?