JONOAK73, I know the importance of getting messages quickly. I'd be more than happy to help troubleshoot what is happening. We do want to have Mobile Data turned on, so you can receive your voicemails. If it is currently off, please switch it the data back on. You can do that with these steps included in the link here,
http://spr.ly/6580DrpRE Let us know how that works, are you experiencing any other issues besides the voicemail?
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The short answer to your question is YES. The cellular data connection is needed for the voicemail application to retrieve and verify any voicemail waiting on the server.
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