Due date is wrong

I have just logged in to make a payment and saw that my account says that the due date is 12/13/2015.

I have paid this amount and verified the amount was taken from my account.

When I view the current bill (pdf) it shows the correct due date for January 2016. 

I want to make sure that this is reflecting correctly as I do not want it to show I am a month behind when I am not.