I have had the same problem as Kevin - I renewed my one seat and added another - but the billing has shown that i now have 3 seats. I only need 2. This was clearly an error. I have a third seat NOT YET ASSIGNED TO ANYONE - but cannot find a way of being refunded this payment made in error.
When I downgraded my plan to only 2 seats for next year, it does not give me the option of requesting a refund - so i have one unassigned seat sitting there and being paid for!!
This is not good customer service :(