Improve search engine position

My question is very simple, I need to find out a way so that when someone is looking on internet for a web site of one my clients, his web site appear within thw 20 first link in the search.
For example if I type “coca-cola” on google the link to cocacola.com should appear within the fisr 20 link shows. I know that I have to pay google to do that but I can find a way to do it, I have written google but they have never answer me back.

thanks