These charges and credits show up when you add, change or delete a service in the middle of a billing cycle. They show credits and charges that have been affected by the change to your service. Also these charges may show up on your first bill to show what partial charges and credits are for the remainder of the billing cycle.
Like most communications providers, Mitchell Telecom bills your services on the first of the month for the month, which means your first bill includes a portion of the month in which you signed up along with the next full month. Your billing after the first month will be without the partial month of service and reflects a single month of service.