how to restrict one respondent only fill in survey only once?

hi all, i am designing survey in Qualtrics and I already use the " Prevent Ballot Box Stuffing." However, when I launched the survey in MTurk, i found there are lots of duplicate IP address so respondents clean their cookies and/or use another device. but my research and filter questions need one respondent only fill in survey once. How can I avoid this?
many thanks for your help and solutions.