Its late and I'm tired so sorry if you've already tried this...
Install HTC software on your pc and android sdk (to get the drivers and fastboot)
Plug in your phone when its on the 4 !'s screen
fastboot flash alpharevs bravo_downgrade.img
unplug the phone, pull the battery, put it back in, turn it back on then plug it back in (or just reboot the boot loader with fastboot)
then try running this RUU http://www.filefactory.com/file/b4a4...811_signed.exe
If that doesnt work see what version it says you're when the ruu says what version you're on and what you're updating to and download the ruu with the same number as the one you already have and see if that helps.