what do you mean by 'haven't received anything from INS'? Didn't you receive a letter stating BCIS received your application? Did they cashed your check? If so, use the receipt number to check the status of your parents' application on BCIS website and processing time. By the way, you need to submit the original I-94. When the application is approved, you will get a new I-94 with new expiration date. Good luck,