I am also 100k & The easiest way to get a refund is just to send them a message on their twitter. https://twitter.com/frontiercare all you need to do is send them your confirmation number & name and tell them you want to cancel & get a refund. They usually write back in a maximum of a few hours telling you it was canceled & refunded.

Anytime I have any issues that need taken care of I contact them this way. Their agents are all very helpful.

Hope this helps.