No, no one can guarantee you a top ranking in Google.
A good digital partner authentically boosts customer confidence with education, clear expectations, and business goal alignment. A great SEO company backs that up with supporting data/evidence, expert credentials, social proof, and relevant case studies.This is because we, or any other SEO company, cannot control how Google ranks websites.
Many of the SEO companies that do still guarantee rankings have taken the clever tack of guaranteeing a certain number of keywords that they themselves choose. In this fashion, they can select primarily non-competitive terms and have a fairly high rate of success. Whether those keyword rankings provide any serious traffic is another matter altogether.
As Google makes changes to their algorithm SEO companies do their best to understand what changes were made and modify your website to give Google what they want.