Unfortunately not.

Your minutes usage is based on a monthly quota: every month your quota will automatically renew, and any minutes that you haven’t used won’t roll over to the next month.

Your minutes are only valid for individual months and you can’t accumulate them. If you didn't use all your minutes from your monthly quota or obtained through 'Earn extra credits' actions, those unused credits expire when your billing cycle ends - they don't roll over to your next month and they don't accumulate with your renewed monthly quota.