Conversion of Credits to Feature Use and monthly Payment

It would be cool if this were possible. To convert some of my over-abundant credits to pay for a month of my account. Because while I have an overabundant amount of credits, they do me no good if you all shut off my access to use the features. It was a silly thing as I forgot a new month was approaching and in the heat of a writing frenzy, I refilled my credits then noticed ahhh another month is here and well now Im stuck with all these credits and am shut out of using them.