A Motion To Quash Service of Summons and Motion To Dismiss. Or you can file a Demurrer (instead of an Answer to the Complaint.) It would be best if you get an attorney to file these motions for you since it's a matter of such importance. There are very short deadlines to file these motions as well. Good luck.
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As Ms. Allen has correctly stated, you would need to file two motions--that is, both a Motion to Quash Service and a Motion to Dismiss. But, do yourself a favor and hire an attorney to do these for you. Best of luck