I'm uncertain what Frontier will or should do in these situations. It seems clear they are not communicating accurate information and this is not the only problem with their website, as you found with the history search. But on the other hand their announcement of program changes was pretty specific so customers were on notice of the change in expiration dates.

There was a recent major change in the appearance of their site but I haven't had time to check whether they fixed any of the bugs I have found.