Chances are you got your free credits the second you hit the next eligible level. I always have, without issues :)
To clarify, as far as I can recall, when you add enough credits to your account that will put you on the next level, the free credits are added even before you buy another card. Normally, you should see a notice from Totem advising you of this but possibly you missed it?
Anyways, I'm sure a Team member can tell you exactly what was added and when :)