1. A system for providing a credit back to a customer, comprising: at least one database, said at least one database configured with service plan details including perishable service units for a first service type allocated to a customer per billing cycle, said at least one database also configured with a payback rate amount for the first service type, and a maximum payback amount for the first service type; at least one processing system for tracking the number of used service units for the first service type, said processing system configured to calculate the service units of the first service type remaining at the end of a billing cycle, said processing system configured to calculate a calculated payback amount for the first service type by multiplying the number of remaining service units of the first service type with the payback rate amount for the first service type; and wherein said at least one processing system is configured to determine a payback amount for the first service type by taking the smaller of the calculated payback amount for the first service type and the maximum payback amount for the first service type.