When people hear your name in a voice-mail or see you in their inbox, how do they feel? Which messages do they want to respond to first (or at all)?
My guess is that they will want to reply to someone who is going to help them; someone who can offer them advice, or come up with just the service they need; someone who’ll give them some useful information. They probably will not be so interested in talking to someone who always wants something from them, or is going to nag them or make them feel guilty, or have to explain themselves.
And please don’t say to them, “Didn’t you get my messages last week?” That puts them way on the back foot. If they haven’t responded, just go into the conversation, or message, as if this was the first time.
Think about it; when you look at your messages, whose calls do you respond to? Put yourself in their place when you pick up the phone, or hit “send.”