The simple answer is no! Any company that guarantees a particular ranking for a particular keyword is being extremely foolhardy.
What we can guarantee is that all of the proposed and planned work for your campaign will be carried out. No-one can guarantee specific results, and you should steer clear of any company that claims to be able to deliver on that promise. Additionally, the authority and power of the number one position in Google has been diluted somewhat due to the way the search results pages are presented (see ‘The Incredible Shrinking SERP – 2015 Edition’ at Moz – https://moz.com/blog/the-incredible-shrinking-serp).
Why? There are an immense amount of factors affecting the position of sites in search results, and no-one (maybe not even Google themselves) can plan or predict what the position of any site will be for a given search term. It is estimated that sites can shift by as much as ten positions up or down with one week within Google’s results!
Ultimately, the search index is Google property, and external agencies can only influence it, not control it directly. Even Google have recently hired SEO experts to help their own sites rank within their own index.