Config Activate at Previous Package Expiry is a feature that allows you to extend the period of prepaid packages by buying the same prepaid package. The following are the steps to activate the feature.
Step 1. Go to Setup Menu - More Menu - AddOns
Step 2. Prepaid Package -Activate at Previous Package Empty - Save
If it has been activated then there are customers who purchase the same package but the previous package is still tortured the active period of the newly purchased package will not be counted / started if the previous package has not expired.