A very unfortunate but common experience in search engine optimization is a mismatch between client and service provider. Many good SEO consultants have complained through the years about clients who refused to implement suggestions, or who made changes without consulting their SEOs, or who otherwise sabotaged relationships. Some of our own clients have paid us and done nothing with our reports. Their rankings continue to be dismal. If you decide you want to change consultants, be sure you have not burdened your SEO with unreasonable expectations and that you have done what you've been asked to do.
Sometimes, the SEO just cannot help you. It may be due to inexperience or insufficient resources. So there is no harm in getting a second opinion. Many dissatisfied SEO clients have found that they first contracted with so-called "black hat" SEOs who used hidden text, page redirection, and other disreputable practices. If you signed a contract with a service provider who created doorway pages leading to your site, or who embedded hidden text or redirecting code on your pages, you may want to speak to another SEO -- especially if you are not getting the results you want.
We can evaluate the work performed by other SEOs and advise you on whether the work is beneficial to you. But if you are expecting immediate results and don't have a spectacular, new, innovative, unique, in-high-demand product or service, your chances of seeing immediate results are slim to none.