This, so hard. I used to do this type of work with the sparkly promise of royalties (on net profit no less, sigh) because I didn't know better. It always worked out to me never seeing a dime AND never even getting the copy of my card (in one case, the company DID sell a lot of decks, and I had to end up buying my own card on eBay).

Royalties are... okay.. if you are working with an established company with a good reputation and a history of good sales AND a known buyer base, but even then it can require a lot of prodding of the company and not much earnings, depending.

Royalties, when it comes to individuals or small indie companies, are (with very few exceptions), going to suck or not exist at all. :(

It's a hard lesson learned. Doesn't excuse the behavior at all-- trust me-- but it is a very common and reoccurring theme.