Hello @angela_5860,
Thank you for your message.
Your credits are refreshed on the anniversary date of your plan. You can see that on your plan page on account page at: https://account.adobe.com/. Look for the Month and day where it says next payment:

If you have more than one plan that has Gen AI credits, you get the credits for that plan on that plan's anniversary date. For example, if you have Firelfly Pro and Adobe Stock, you get the Firefly Pro credits on that plan's anniversary and the Adobe Stock credits on that plan's anniversary date.
My best,
droopy