No worries about this! after the plan being expired, you can choose a new one directly from oodi app.
If you to renew the same previous plan :
- choose to re-subscribe to this plan
- press "pay now"
That is it! your monthly plan is active and you can use it directly
If you want to choose a new plan :
- choose another plan
- select plan subscription for one month or three month
- choose the amount of voice and data you prefer
- press subscribe
In this simple way, your plan is active and to make your life easy, you can just enable your plan auto-renewal option. Just make sure you have enough balance