Virgin Mobile is a 'virtual' mobile network operator but ports mainly on the Sprint CDMA network. Unless your phone specifically had Bell firmware or was porting on Bell, flashing the Bell version would be wrong and could, nay would, cause a brick. Thankfully, though it appears to be only a soft brick and may be recoverable by re-flashing compatible firmware. Unlike Sprint and Virgin which are CDMA networks, Bell is GSM so I'd very much doubt that the firmware you were trying to flash was compatible with your phone. The fact that your phone is still trying to boot suggests that the bootloader is still intact but the system itself has been compromised. Can you remember what Android version your phone was on the last time it functioned normally? If so, I would suggest you visit Sammobile.com or androidfilehost.com and find the same version (or higher) for your phone and then flash to return to stock or near stock. You can always re-root afterwards or flash a custom ROM when your phone is back to working normally.
Since you can get into download mode, you can flash custom recovery in case the stock file you find is a zip file to be flashed via recovery. You should be able to get into recovery mode if you try the button combo again after you have flashed custom recovery via Odin. Otherwise, if it's a *.tar file, just flash directly with Odin.
