I say cancel your checks--USCIS can't do anything.

Two Canceled checks won't hurt your credit. Why give them your hard earned money for their lousy service? If they did half what they are paid to do, you would hot have to sent those checks. And, as common sense, since they have not started your process, you should be able to call them and cancel it. They don't give you the opertunity, so cancel the checks.... Send your money to China to help those poor victoms if you can.... Your money will be put in much better use..... Congratulations... You are free don't be afraid of USCIS any more...