View source for CallerID is not dropped if balance is zero

1. Make sure you have the functionality [[Calling Card Groups | Leave CallerID assigned to Card when balance is empty ]] disabled
<br>
2. If it is disabled and the user made a call and balance is zero and the callerID is there, there are a few reasons for this:
<br>
* CallerID was not dropped because the user in the same call can use [[Card TopUp | Calling card top up]] to increase their balance on the card
* CallerID will be dropped once the user makes a new call to the system and the system will ask for new PIN