Customizing Subify widget on checkout

we want to et up a plan as follows:

Customer pays $7 first charge

Customer pays $40 second charge 14 days later

Customer does not get charged anymore (subscription expires after 2 payments).

However, when we set this up, during checkout the script says: "First payment $7.00, then $40.00 every 14 days"

But this is not true, the customers will not pay $40 every 14 days, they will only pay $40 ONCE after 14 days.

What can we do about this, how can we edit this text?