Try pulling out the hard drive from the ps3 formatting it to FAT 32 on a pc then put it back in then try to install OFW 3.60 it should work my buddy had a similar problem and that did the trick, he was stuck in Recovery mode for a while before doing the above method. PS3 only reads Fat 32 so i hope that helps.
Other thing to consider if you are using legit firmwares and no matter what you have the same error with data corrupt it may be the actual hard drive that is goosed , have you tried another hard drive ?
You probably could of just went into recovery mode then do an option 5 from the recovery menu (option 5 is Restore PS3 System) which would of fixed your corrupted hard drive errors although you would lose all your data and save files but none the less it works like 75% of the time, sorry for the late reply and sorry to hear that you have to deal with Sony's Bs Customer Service.
The Restore PS3 System i bet is what sony is going to do for you and then after that install the newest firmware update the same way.
don't send it... There were 2 versions of 3.56... tell sony that v1 was responsible... and you will sue them if they don't do it for free... they will...!! But there is a high probability that you get back a 160gig slim... that is what's happening these days.