Malphite getting CC'ed during Unstoppable Force

Happened to me during a game I had with Malphite midlane, my opponent was Ahri and what happened was that when I used my ultimate towards her she used charm and my ulti stopped. I don't have a ss to prove this or a video cause my pc is kinda old and cannot record so I can prove it although I strongly advise you to look at the matter.