Hey Steven! I can help clear up some confusion here.
When you activated your SIM, it did charge you the $9.99 again, but it didn't charge it to your card. It charged the account balance credit that you had from the original $9.99 purchase. So when you purchased the SIM card, that $9.99 for the plan was put on your account balance to be used for the activation. So there were no double charges there.
A week later, you seem to have activated another phone on another account under your family plan, which was for the $19.99 plan. If you only wish to use the one account, we can cancel and refund the second one. Just head over to our live chat support between 10am-5:30pm EST for further assistance.