problems with tv

I got a 46 inch Apex tv I believe itll be 2 years in sept. I got the warranty where I purchased it at target. I lost the receipt and now they are saying theres nothing they can do about it. Isnt there some way they can look it up so I can get it fixed? I was watching a movie one day and all of a sudden it just shut off and wont turn on. no warning or nething.