Please I went for an interview last month on the...

We would like to inform you that you have to go to the headquarters designated for the interview and avoid all the mistakes that were made in the previous interview, on the basis of which the rejection decision was issued. If you do so, your application will be accepted, God willing.

In addition to the previous response, we refer to the following information:
If your application is denied under Section 214(b), it means that you have been unable to satisfy the Embassy officer that you are visiting the United States for the reasons stated on your visa.
  The embassy employee may suspect that you plan to stay in the United States long term.
To overcome this rejection, you may need to prove that you have strong ties or affiliations with your country. Some possible ways to avoid this problem include:
Proof that you are married, have children or have another family in your home country and you must submit the marriage contract and birth certificate of the children
Proof of a real estate lease contract or private property in your country
Proof that you have a job in your country, by providing an answer or a job offer waiting for you upon your return
Provide evidence that you have other reasons to return to your home country