We have all done this at one time or another. Called someone, maybe left a message and then did not follow up the call if we did not hear back from the person. In sales, that could lose you a customer. People have lives and you never know what is going on in them. Be persistent. If you made the call and did not hear back within 24-hours, then call again.
Yes, it may feel uncomfortable but that just might be the person who returns your call and says thanks for calling again, I have been meaning to get back to you and life got in the way. It happens. Do not give up on any potential customer, particularly if you got the lead from an online lead generation company and it was pre-screened and pre-qualified. That means the people are interested and want information.
Sometimes those who do ask for information suddenly find themselves second-guessing their actions, but remember this: They made the contact asking for someone to call them. They are part way down the path to purchasing a policy. It is up to you to be there when that moment happens.