The Ubigi Monthly Plan will automatically be cancelled if the payment fails at renewal.
This may happen if the credit card you registered for the monthly payment has expired or if the payment did not go through for any other reason (ex. rejection from your bank, etc.).
In this case, you just need to subscribe again to the Ubigi Monthly Plan of your choice and enter your (new) credit card details during the subscription process.
When you cancel your subscription manually, it will also appear as cancelled before being removed from the tab “My data plans” on the last day of current renewal.