HSPA change amount of rings before Voicemail on Telus
First you will need your voice mail number, on you BB OS 7 you would hit "send" key then click you BB menu key and choose options from the list, then choose Voicemail
your access number is what you need without the +1 in order to change your number of rings.
Dial *61*insert your voicemail access number here**30#
then hit send. You've just set your ringing time to 30 seconds before the call goes to voicemail.
Dial *61*insert your voicemail number**25# then the number of seconds would be 25.
It can only be changed in increments of 5 secs all the way up to 30 seconds.
Hope this helps