There u go contact steam to reset the cd key
Link:-
CD Key Reset Process - Steam Support Wiki
Current CD Keys are comprised of 18 numbers and letters (Prey) or 25 numbers and letters (Valve games) arranged into five groups of five characters separated by hyphens:
Prey example:
AAB1BB2C345CDD6E E7
Valve game example:
1AB2C-D3FGH-456I7-JK8LM-NOP9Q
If your CD Key fits one of these patterns, please see the Contacting VALVe Billing and Support article for instructions to create a support case to provide the following materials:
* A scan or digital photo of the CD Key with the words Reset To and your Steam account username written in permanent ink on the reference card or sticker (without obscuring the CD Key)
* A scan or digital photo of your retail purchase receipt (game must have been purchased within the last 90 days - we do not accept receipts from auction sites or in cases in which the game has been resold by another individual)
* The Steam account username you would like the CD Key moved to
CD Key Scan Example
Please see the example below to see how your CD Key image should be sized and noted. Please write your account name - in the example you will see the account name "support" - or your support incident number (you will need to submit your incident, write your incident number on the CD Key, and then update your case with the scan if you are not sure of your account name). EA CD Key Scan
If you do not have access to a scanner or digital camera, you may complete the CD Key reset process described for Half-Life, Counter-Strike, and Blue Shift CD Keys which is outlined above (you do not need to include $10.00 USD for the CD Key Reset Service Charge).