You need to contact the National Visa Center. The details are below and in the attached link. The same website found in the link also provides instructions on the NVC process. However, if your case was approved so long ago and you have not been in contact with the NVC for more than a year, you risk abandonment as the NVC attempts to contact petitioners and you must maintain yearly contact IF your priority date is current. It is possible that you immigration category is not yet "current" meaning that you may have to wait for the priority date (date your I-130 was filed) to match the visa bulletin cutoff date. As this can be difficult to understand, I recommend you have a consultation with an attorney whether myself or one of my colleagues.
Excerpt from NVC website
The NVC’s e-mail address is NVCINQUIRY@state.gov.
E-mail is the NVC’s preferred method of communication.
Note: Use your personal e-mail account to contact the NVC. If you click on the email address above and your computer does not automatically connect to your personal email, copy and paste the above e-mail address into an e-mail using your personal e-mail account.
In order to ensure a prompt response:
•Enter your NVC Case Number or USCIS Receipt Number in the Subject Line of the e-mail.
•Provide the applicant’s name and date of birth and the petitioner’s name and date of birth.
•If the petition is employment-based, include the employer's company/organization name.
•Provide the attorney of record’s name, law firm and address (if applicable).
Customer Service Representatives are available to respond to case inquiries.
Telephone number: (603) 334-0700
Hours: Monday through Friday from 7:00 AM to 12:00 AM (Eastern Time)
You must include the following information to receive a case specific response:
•Your NVC Case Number or USCIS receipt number
•The applicant’s name and date of birth and the petitioner’s name and date of birth
•If you are an attorney, include the name of the law office requesting the information
Note: This service requires the use of a touch-tone telephone.
I agree with my colleague.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.