急问：intent to deny because of missing fingerprint

Just receive a lettler from USCIS，intend to deny my I485 application because I didn't appear on my scheduled fingerprinf appoint time. But in fact I did show up and did the fingerprint. What should I do? Any input would be appraciate. One thing is I can send back the copy of the receipt of fingerprint to prove that I did the fingerprint. Do I need go to local office to ask to do foingerprint again?