Trouble with number of rings before voicemail comes on

About two weeks ago, Boost sent me a text message saying I must reset my password. I followed their prompts to the letter. I have had my Samsung phone for over a year with no problems, and my voicemail has always come on after 5 rings. Now it comes on after 8 rings which is way too many. Boost says there is nothing they can do from their end to change it back to what it was. That is obviously wrong because there is no instruction I can follow to set the number of rings before the voicemail comes on.

via Cell Phone Forums (French) http://cellphoneforums.net/fr/boost-mobile/t364221-trouble-with-number-of-rings-before-voicemail-comes-on.html