Hi, I am USC and planning to withdraw my signature on Form I-751 filed jointly with my immigrant spouse. His case was initially at Nebraska office, however it was transferred to another USCIS office some time last year (according to uscis website) , and I do not know where the new office is (since we no longer talk). I have sent the withdrawal letter to 2 addresses (one to Nebraska office 2 weeks ago and other to Elgin Lockbox a month ago), but I am afraid it will never make it to his files. I am guessing his case was transferred to Chicago Field Office since it is the closest office, should I mail my withdrawal letter there as well (not sure if they handle I-751 there) or just wait to see for his case status to be updated to “withdrawal acknowledgment notice was sent”? Do you know any uscis phone number that I could call to find out if the letter makes it to the files? Emma was useless when I tried. Also how long it normally takes uscis to issue the withdrawal acknowledgment notice to the petitioner after they receive the withdrawal letter. Any info pass along is much appreciated. TIA!
