If a phone rings once and then goes to voicemail or rings only briefly, it usually means either that your call is blocked or that the phone is not receiving calls at all. If the phone rings five times and then voicemail picks up, it's more likely that the person on the other end simply isn't picking up the call.
When starting a Voice Recording you can choose between 3 different recording modes, you can select either Standard, Interview or Speech-to-text. When using Interview mode the sound is amplified from the top and bottoms of the device and reduces the sound from the sides. This mode works effectively when recording sounds in a noisy surrounding.

Hi, you have reached (names) voicemail. If you want money or to sell us something, we a) gave at the office, b) already have it, or c) don’t want it. If you are a friend, trying to give us money or just want to talk, then leave a message or try my cell phone number. I don’t know who you are, and I don’t know what you want.
Great question! Although I don’t know if there is a specific function for this on your particular phone, the best way to save the message is the simplest. Turn up the sound as high as you can and record it onto a digital recorder (like you would use for a lecture), a cassette recorder or your cell phone if you have a voice recorder on it. Then save it as an MP3 on to your computer for safe keeping. You can also Google your vtech model number to see if you can find an owner’s manual. They might have a way to save a recording in there. Probably not, but it’s worth a shot.