I'm sorry to hear that you're having this issue.
I'd recommend calling back the service center to see if they can assist in a repair. If the firmware was the cause of the problem, then there may be some remedies available.
If you're not able to get assistance, get a service ticket number from the person you talked to, and I'll see if I can assist.
Samsung sent me a firmware download for my LNT4661F My picture Now looks like an egg droped from a high building. Customer support could not help. Is there anyway I can undo this. The TV appears to be ruined. The thing will not alow me to update again because I now have the latest version and will not let me redo.