Champion not moving in game

I was playing a match earlier as Garen top and at one point about 10 minutes in the match i started to notice it was reacting slower than it should but there was no change is ms or fps but since it was just a slight delay i just started backing up into the turret range and then. . . it stopped moving. I was right on the outer edge of the turrets range and clicking to move back further into its range but nothing was happening. I kept clicking over and over again in an attempt to move but it was frozen in place even though i could CLEARLY see the little green arrows on the map whenever i rightclicked somewhere. I wasnt lagging either because i could perfectly watch as the enemy teemo simply walked right up to me and autoattacked me to death before i had any chance to try and back (B) and just killed me because they noticed i wasnt moving at all. It really ticks me off because i had to restart the client and by the time i managed to relog into the match we were already too far behind to do anything since it was already a 4 vs 5 at that point and with me being out of the match for all of 3-4 minutes it completely messed us over. I dont find it fair that this happened during a ranked match when its the first time i have ever had this issue and i was playing a match right before with no issues whatsoever.