Weird Adwords Voucher issue

Hi,
I last night i brought a $250 adwords voucher from a friend , but for some reaon i don't see option enter voucher code in the "Billing Preferences" under MY Account tab.i used $50 signup link to to setuo this account & trying to add this voucher to that account , unfortunately i don't even see the option to enter
voucher, i created few other adwords accounts using $50 signup link earlier(using different names & CC's ), but never used any vouchers on those accounts. Any help is appriacted

 

Its been said that option to enter coupon code is not available to accounts created with signup link. I have created an account without signup link, I still see way to enter coupon code.

Do you want to sell yours?

 

If you still have it, send me PM. I would be interested to buy

 

I'm interested to buy your voucher. If you want sell it PM your offer

 

thanks guys, will create another account without signup link, i have NO plans to sell my voucher, it took almost one month for me to buy this voucher from my friend, they are hard to find

 

Thanks for info