Bought a replacement engine from them $3,400 plus ...

Bought a replacement engine from them $3,400 plus tax got the engine pretty quick installed it and noticed a slight tick on the bottom end.. Called rockauto.. They say call ATK call ATK they say change the oil and drive it.. Mind you this was a brand new engine so I change the oil and continue driving keeping them updated about the tick that progressed to a knock was getting worse.. Well about 2 weeks go by like this and the motor exploded... Literally exploded 300 miles on the engine had to pull the motor out and send it back to ATK for them to "inspect it" to see if they will warrantee it... I don't understand I paid over 3000$ for this engine that blew up after 2weeks and 300 miles had to wait 8 days for the motor to get to them for inspection now they are telling me 10-15 buissness days for them to find the cause of the problem it's been 2 months now no response from them and I'm out over 3000$ and a engine for my truck... They took my old motor as a core charge so literally truck is in my driveway with no engine for it