deleted huge Gift Certifactes mistakes and still seems users are using GC's

Hi,
My client accidentally sent out $100 gift certificates to all her customers two weeks ago (big oops). We did send an email blast explaining the issue and not to use the gift certificates (and offered a generous alternative sale). I've looked through every forum post that I can find.

So we went through the table and deleted all the gift certificates and they are no longer showing up in ZenCart admin.

People are still occassionally clicking on the links in the Gift Certificate emails they were sent and still using the gift certificates. We can't figure out how because we deleted the GC's. Is is something in each client that we need to delete? Do they have a customer balance field?

thanks!

What method were the Gift Certificates created?

If you look in the coupons table do you see any in there marked as:
coupon_type G

for Gift Certificate?

Anything set to:
coupon_active Y

is still available ...

You can also check in the table:
coupon_gv_customer

to see the customer balances ...