Who should I contact--Raleigh, NC

Question

I have a Ruud Achiever 10 seer..Warranty 5 years. Contractor states out of warranty. I travel and out of my condo 3 mos. at a time. The last time the a/c was turned on was last summer and my son stated while staying over night that It was not cooling and needed Refrigerant. I forgot all about it. Cam home in April turned on A/c-not cooling. Called contractor- compressor frozen. I called on April 25, He cancelled appt. on April 28 and came on the 30th. I had the electricity turned on April 30, 2005. He says it's out of warranty. What should I do? It's so hard to trust people these days especially when they know you don't know about these things.