iPhone doesn't turn on or restore after an unsuccessful jailbreak and restore
I've got an iphone 3gs. It's locked to one carrier, then jailbroken, then unlocked, then I restored it (stupid stupid me), and then tried to jail break (with redsn0w) it again with redsn0w but cydia didn't install properly. Tried to restore it again but I couldn't because the baseband was upgraded in the jailbreak (from what I've read so far, I assume it's that).
So I gave up and brought it to a cell phone repair shop... Got it back and now it doesn't turn on, period.
I tried restoring it with iTunes and get an error 28.
Before taking it to the store it had 4.2.1 on it. I have no idea what it is on it now and don't know what to do. I can't afford to buy a new phone right now... Please help? Thanks in advance.
012711: Not liking Apple very much at the moment...