So points.com is weird. First, after I made the login, I could find no way to purchase points of any kind—only exchange or redeem them. So I had to google points.com buy frontier points or similar to find a page where I could buy them.

Once I bought them, there was no immediate email confirmation as was promised—I recommend taking a screen shot of the confirmation page.

The 1k miles showed up in my Frontier account about 12 hours later, along with an email showing same. I waited about 3 hours, as instructed, and called in, giving my reason as "to reinstate my miles." He said it would take him several minutes on hold with his support team to do this, which I said was fine. He already knew what I was doing—using the 1k from points.com to get my old points back—but I'm not sure if he knew because of notes in my account or because this is a general policy.

After about 5-10 minutes on hold he came back and said all the points had been reinstated. I checked 5 minutes later and they're all there.

So the moral is that at least in my case, with no activity since April and with points that expired some time in December, I was able to get them reinstated for $26 (which also gave me an extra 1k miles). (Keep in mind that all of my deleted points were accrued shortly *before* the 3/7/15 change to 6-month expiration...no idea if that made a difference.) I would of course have preferred no cancelation in the first place, or a warning of cancelation, or a free reinstatement, but I didn't want to spend more time arguing. Overall I feel OK about the whole thing considering I had assumed I'd get nothing back.