Technically you write a letter to USCIS to the address on the I-129F petition approval. since the case is now either at national Visa Center it is a courtesy to email NVC and the consulate as well depending on where the case is located currently and they will return the Petition to USCIS for revocation.
Lynne R. Feldman, Attorney at Law
Concentrating in Immigration and Nationality Law
2221 Camino Del Rio South, Suite 201
San Diego, CA 92108
phone: (619) 299-9600, facsimile: (619) 923-3277
email:
[email protected]
website: www.immigrateme.com
Formerly Adjunct Professor -- Immigration law
University of Illinois College of Law