Howdy Lamac48,
It sounds like you are having sound and Visual Voicemail issues. We know how important having a working iPhone is for you, and you’re in the right place to find a resolution.
Please make sure your device is running the latest iOS version 14.2. Then test to see if the issue has been resolved. Please let us know what happens.
As with any update, it's always a good idea to create a backup beforehand: How to back up your iPhone, iPad, and iPod touch.
How to update your iOS device: Update your iPhone, iPad, or iPod touch.
Here's a resource that can help with your Visual Voicemail:
• Set up Visual Voicemail on your iPhone
Specifically, use these steps:
• Get help with Visual Voicemail
If you need continued assistance, then please reach out to our AppleCare phone support team via this link: Get Support.
Take Care!