iPhone voicemail indicator not updated

Last night, after receiving a voicemail, the indicator remained on. The real annoyance came from the fact that I also did not receive notifications about new voicemail. Naturally, I tried restarting the phone, leaving myself a voicemail from another phone and then retrieving and deleting it. Nothing worked, it just seemed stuck on.

After the call to Telus was escalated to someone else they asked me to retrieve and delete a test voicemail they had left but instead of hanging up, to disconnect using ** (double asterisk). The explanation being that somehow the network would not be aware that I disconnect by pressing "end" therefore not updating the voicemail icon. By using ** the call terminates on their end.

It worked, for now at least.