A/C is not working

My Prius kept draining frion and they couldn't find a leak. Finally, a few mechanics later, they said my compressor was bad and replaced it. It was 1200+ for the repair, but it has a 12 month warranty. A/C was already getting less cold only a couple months later, but when I took it in, they said it's fine. Well, now it's been 10 months since the repair and it's blowing hot air. It progressively got worse and worse and I've been dreading taking it back but finally am. I'm afraid they'll tell me it's something else entirely and charge an arm and a leg. It's a 2005 with 125,000 miles.

 

I forgot I posted this! Wow, 3 weeks and a lot has changed.

Update: I took it in and they said now the evaporator has a leak. This is an Autonation Toyota dealership with a decent reputation. The repair this time would cost $2000 plus the $130 it cost to recharge it and diagnose it. None of it under warranty because it's a "different part" even though it's the same problem. They recommended I just refill it every few months.. I live in Florida and can't go without A/C. As far as I know, it had not been in a front-end collision, but had been rear-ended previous to my ownership. The mechanics I know told me to get rid of it, so I did. I traded my little old Prius for a shiny new (to me) 2010 Prius. Wasn't thrilled because now I have a car payment, but was happy enough with the last Prius to call it a fluke and give it another shot. Thank you for your replies, I am sorry I forgot to check this thread again! I have searched around and have seen a couple other 05 owners with similar issues.