Credits not disappearing?

I was looking to cancel my membership with two credits left. Before I canceled it reminded me I have two left. So I used them. When I refreshed the page, it still said I had two credits remaining. So I purchased two more books then the same thing. I did it a third time and still the same. Anybody run into this? Thoughts?

EDIT: The credits have been redeemed to zero. It seems that when I switched browsers from chrome to Microsoft edge the glitch fixed itself (perhaps coincidentally).