If you call your service provider, they should be able to clear it, provided all messages have been read and you don't have any voicemail waiting to be heard. They can send a "0" count through their switch (processor) to your device which will in turn clear your message waiting indicator.
Answers & Comments
If you call your service provider, they should be able to clear it, provided all messages have been read and you don't have any voicemail waiting to be heard. They can send a "0" count through their switch (processor) to your device which will in turn clear your message waiting indicator.