An account management engine for managing at least one prepaid wireless service account can include a calculation logic module that includes at least one scheduling algorithm configured to calculate a message delay time, the expiration of which triggers a continue message to be sent to a service switching point (SSP) instructing the SSP to continue an established call. A method for managing at least one prepaid service account can include calculating, based upon at least one scheduling algorithm, a message delay time, the expiration of which triggers a continue message to be sent to a service switching point (SSP) instructing the SSP to continue an established call.