How 8B describes it is pretty similar to what I get ; the tier miles balance takes into account future booked travel ; once 50k is attained it changes to state "Congratulations! You have achieved the required tier miles to renew Gold. " .. One difference is that I only get an asterisk rather than a cartoon character
Has the "you need x tier miles...." value changed on the front page?
If it hasn't credited , I would suggest a quick phone call might be in order