SEO for a specific key term . Rank me top 10

Hello I own a free online games website and i want a professional SEO expert to help me rank top 10 for a specific keyword The keyword i wish to get on top #10 is "free games online" I rank for this keyword on position of around #50-#70 which is very good What i want is that you manage to get me on top 10 and leave me there for at least 20 days So project requirements are simple: With whitehat professional link building techniques you have to built at least 90% permanent natural links related to gaming niche and boost my SERPS to make me rank top 10 NO SPAMMING , BLACK HAT METHODS, METHODS THAT WILL RUIN MY SERPS The site has a lot of SEO work on so you should be able to do it easily if you are a professional I seek a fixed price and a short as possible timeframe ( around 1-2 months ) to get me there PAYMENT TERMS I will pay around $500 for this whole project %40 will be put in milestone in the begining of the project and released after top 10-20 ranking achieved and retained for at least 5 days %60 will be put on escrow and released after top 10 ranking achieved and retained for 20 days GUARANTEES: If you dont manage to make me rank top10 then you should cancel the escrow payment back to me and i have no obligation or responsibility to you Regards