I had about 50k miles on Frontier primarily from my Midwest airlines travel. I had checked a couple of months ago and I had recent rental car activity to keep my account in good standing. I tried to login to my account yesterday and had to change my password. When I did, there was no FF account associated with my account number. What happened to my miles and how do I get them back?

I tried to email them but had no luck because the only option had to include flight information, which wasn't relevant for my issue.