Licensing boggle for church

We are a church and purchase non-profit licenses through a vendor. A couple of months ago we needed to add a user and had 5 licenses. We thought we needed to purchase an additional license. However, in the meantime, our staff needs changed and we now have 5 paid licenses and only need those 5. But, our account shows that we need to pay for a 6th license but we no longer need it. There doesn't seem to be any way to change what we need.  What should we do?