What's up with VIP golden keys?

Just went to the Borderlands VIP page to pick up some more golden keys for the Borderlands remaster, and huh…can’t right now. The tile is dimmed, and when you click on it the dialog comes up without the redeem button.
And this has appeared
text
Huh? I can’t redeem more than XXX numbers of keys per “period”???
Why on Earth not? I ain’t hurting anything by redeeming keys, am I?
Just seems weird.
–RoA