16 Man league is giving me problems over only having 6 votes for a trade veto

This guy in my redraft fantasy league is insisting that it is unfair that it only takes six votes out of the 16 people in our league Veto a trade. His trade has been vetoed multiple times and he and his trade partner keep accepting it over and over again. What should I do in the situation? My other league mates are very tired of this person‘s antics.

The trade in question was Travis Kelce, Josh Jacobs and DJ Moore for Kyle Monangai, Dalton Schultz, and Shakir.