Periodic Billing: Billing due list not coming same as Billing Plan

Dear All,

        While creating contract system given 4 Billing Plans (Billing Dates) and against to that contract# while generating billing through VF04 system displaying 3 billing due list. How to get billing due list same as Billing Plan.

Contract: Billing Plan

T.Code: VF04 - Billing due list against to the contract

System consolidating manually changed date line items to one document in billing due list. 

Thanks & Regards

Parviz