Best answer by Mats
Wait till your base plan is almost up for the 30 days and just buy a data booster in the mean time. Boosters don't expire. Then when your base plan is about to expire buy the base plan that you want. If you change it right now you'll have to pay the full amount.
https://www.koodomobile.com/prepaid-plans?INTCMP=KMNew_NavMenu_Shop_PrepaidPlans
View original
https://www.koodomobile.com/prepaid-plans?INTCMP=KMNew_NavMenu_Shop_PrepaidPlans