There has been much talk about SEO (Search Engine Optimization) for the past few years and with it many scams have followed. Often scammers send out emails saying they can do SEO for your website and guaranteeing you that they can place you on the first page of Google for $$$ per month.
The first issue with that is no one can guarantee you a specific position on any page of any search engine. Even if someone worked on the board of directors for the search engine, unless you're referring to new start-ups or mom-and-pop type operations, it would be highly doubtful.
Secondly, Google has a free map service that you can sign up for to promote your business. Instructions are available here -> places.google.com. Therefore, unless the third-party is either hosting your site or providing some other reoccurring service, there's no reason to charge you a monthly service for one-time SEO service. It takes no more than two hours to set this up.
Third and final, SEO has many parts to it. There are multiple ways to optimize your site. If you invested lots of money optimizing your site, you still may have to do some serious marketing. Don't be fooled by the SEO hype. A website is very much like a physical store: you need to advertise in order to get more business.