Frontier Airlines Scam when they cancel a flight on you Bradenton FL

I had a flight with Frontier, and they canceled it on me. They sent me an email saying it had been canceled in April 2022. I called yesterday, Sept 22, 2022, and was told the money was lost because I didn't use it in 90 days. 

I never was informed about a 90-day period, and the emails say nothing about that. Instead, they gave me a travel voucher to use for $329 dollars. When I went to rebook a flight, I learned the travel voucher doesn't cover anything but the base flight. So on a $345 flight, the travel voucher covered $7. I would need to fly 49 times in 90 days to use the voucher. It is a scam at this point. 

On top of all this, when they canceled my flight in April, they canceled all flights from the local airport till November 2022. So I couldn't even fly them if I tried in that time period.