"Sounds to me like you are just a dumbass. You can't re-register your serial number to another account once you have already done it. Maybe read a little, use some common sense, and use their Support system on the website to submit a ticket instead of being a complete idiot and just blaming Valve for your own stupidity."
from Steam support:
If you do not have a copy of your receipt for the recent purchase of the game, please include a money order or bank cashier check made out to Valve Corporation for $10.00 USD (ten dollars in United States funds) to pay the CD Key Reset Service Charge
Your CD Key will be sent back to you via US Mail once it has been reset. Please allow 6 to 8 weeks for the materials to be mailed back.
..so they want $10 and 6-8 weeks to reactivate MY game. They won't even take a personal check. Yeah, great company.
F-them. Steam sucks.
This comment was edited on Apr 20, 14:18.