Fut champs cheat

I was playing fut champs, winning. My opponent quit after I took a two goal lead, it then knocked me out of ultimate team, when I went back in it counted as a loss. Either this person is cheating or something is broken, please respond with how you will make this right. There were no internet issues and I have a screenshot/recording of the issue taking place and the player Xbox gamertag. (Though your system will not let me attach the video proof) please contact me directly for this I have instead given screenshots