I have abour $400 stuff still in pending status after several days, and my payment is due 8/3, so I tried to pay more than the balance Citi shows and it wouldn't allow me to pay anything beyond current balance online.
I am going to call in and try to make the payment for the greater amount today. Will post whether I succeed.
The only way to bypass this city blockage of over payment is to pay through your bank account if you use their bill pay service. There is no way for them to refuse. That is what I do with my Citi Premier Elite card.