How to get lost voicemail back after switch to iPhone?

I lost my saved and very important voicemail when switched to an iPhone recently. I was able forward eve initially, but it stopped about 2 weeks after conversion.

Contact the carrier that your device runs on. The main reason you are not getting your voicemails is because Apple's iPhone uses a different service to check voice messages. Basically if you are some simple phone you will have the message, but if on an Iphone will not.