请教8老师：父母来美(上次来申请延期，没做Biometrics就离开）

请教8老师：爸妈2020年2月份来美国，9月份离开。中间申请延期，但是没等到Biometrics表下来就离开了。后来我递交了withdraw I-539的信，但是还是收到了延期被拒绝的信。“Please note, USCIS acknowledges the submitted withdrawal; however, due to the request not being signed by the applicants, USCIS is unable to process the request. USCIS is denying your application as a matter of discretion. Should you seek to re-enter the United States as a B nonimmigrant, you will be required to establish your admissibility again and be granted admission as a B2 nonimmigrant by U.S. Customs and Boarder Protection."

请问，这种情况该怎么处理？爸妈想最近来美，是不是之前的签证不能用了？如果重新申请签证，会有很大的几率被拒签吗？