Throwing Games by Surrendering Right Before Victory and Deleveling

Is this something people can be banned for? Had this happen in my promos in flex queue.

It seems to be their MO.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2599939483/48789520?tab=overview

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2602238147/48789520?tab=overview

To add insult to injury I matched against them in the last game of my promos and they decided to break their surrender streak and win. Said remember us and that I didn't deserve to win. I don't get why people do this.