ask him, why he signed up first ?
If he got a reason, what happen ?
$300 a month? ask yourself why did you want to save $300 a month into something that you cannot use until a certain period of years later. what was the original purpose?
has that purpose disappeared that cause you to not want to commit to $300 savings a month anymore?
how long was the endowment for? 10years, 15 years, 20 or 25 years?
20 or 25 years is a tough commitment i would say, you might be better off losing the $300 X 18.
If you want to save money for year 25, 5 years later you can buy a plan for $375 per month.
if you have found a super good investment that your $300 a month can be put to better use, are you able to save $300 in the current savings plan and still invest $300 into that investment?