The following operations are supported. For a formal definition, please review the Service Description.

• AddCreditColor
  Insert credits for users (Color).
• AddCreditMoney
  Insert credits for users (Money).
• AddCreditTotalPages
  Insert credits for users (Total Pages).
• DebitColor
  Remove users credits (Color).
• DebitMoney
  Remove users credits (Money).
• DebitTotalPages
  Remove users credits (Total pages).
• GetBalance
  Get the balance of user credits.