Did you fully listen to the voicemail message of hang up/disconnect during the recording. If you don't listen to the full record (or mark deleted during the recording) generally the carrier won't send the "VMI off" to the device.
If that fails, you can call yourself from a different line and leave another voicemail, on you get the notification for the new voicemail, go in and delete it. This should clear the stuck indicator. This is what is described in: KB10036-New voice mail indicator displayed, but no new voice mail messages exist
As an aside, I also question the "Indian Symbol" comment :P