A Search Engine Optimizers uses all the spam techniques and ends up with your site getting banned, then what! I am not sure if you could or how you could bring the firm, the so called seo expert firm to court room. The seo firm could also question of the unachievable target required by you. The search engine optimization is a long term effort and it is not advisable to ask your seo firm to give quick results.
It is on Search Engine Optimizers to give details about the time and the risk behind the quick results much in advance. Some points is also to be considered before you go out and hire an seo firm. Lets look at the few points you should keep in mind before going out for a seo expert.
# No one can guarantee a #1 ranking on Google.
# Be careful if a company is secretive or won't clearly explain what they intend to do.
# You should never have to link to an SEO.
# Some SEOs may try to sell you the ability to type keywords directly into the browser address bar.
# Choose wisely.
# Be sure to understand where the money goes.
# Talk to many SEOs, and ask other SEOs if they would recommend the firm you're considering.
# Make sure you're protected legally.