2005 chevy silverado 1500 LS hybrid 5.3L wont crank wont start

What is your question?

I've had this truck for 2 years and one day after work drove it for 20 minutes and parked it waited for gf to come outside her house I turned truck off for about 10 minutes or less and went to start it and nothing no click no crank headlights come on and dash lights work... I had a shop here in town they had it for 5 months and after them saying they don't know how to get it running they want to buy it off me super cheap I told them no and they told me come get my truck and they had it all taken apart I had to pay another mechanic 1500 bucks just to put it all back together and I gave the other mechanic shop ketchikan auto works around 3k for them to say they don't know what to do but they wanted to buy it off me and they wanted me to pay 60 hours of man hr for them to work on it after they had me buy parts up to 2k for them to be wrong parts I have no idea what to do this truck was awesome before one day just wouldn't start