What do you mean by VoIP account? What type of an account do you have exactly? Are you talking about wireless home phone, prepaid, or a postpaid account?

Also see this page: 

It’s home phone. I’m using a vtech wireless handset. It stopped working a couple of days again.

The plan is called “Unlimited Canada-wide minutes”. It is wireless home phone. I don’t know what a postpaid account is. I pay monthly.

Oh you mean the wireless home phone with the wireless modem that you connect a physical phone to? That's not a VoIP setup. Does the phone say anything when you press and hold 1? You should be getting some kind of prompt.

I was told that calls would be carried wirelessly over the Internet Protocol. I assumed that was Voice over IP. Thanks for the correction.

My problem has been resolved. Something, possibly a brief power outage or spike, cleared the vtech phone’s memory, including the phone number used to retrieve voice mail. Once I restored the number to the telephone number on the account, everything worked as expected.

Thanks Sophia and Goran for your help.