Test Cases and Use cases for subscription plan

i want to test Subscription plan in manually the project is based on create/add employees, in subscription plan have 4 types 1.Mini 2.Basic 3.Standard 4.Pro that have different-different feature(like in Mini plan allow access only one application,in basic allow 2 application access(that company can use 2 applications)) and maximum Users Range also defined with subscription plans.and frequency for plan also can change like monthly,quarterly,half yearly and yearly basis. like i write use cases for Upgrade plan,Downgrade plan,Discount,Edit,Change Frequency of plan in mid of month.