Broken chat in client

So I've wrote a ticket about this before and couldn't get any help from support, but this is an issue I can't ignore anymore. Literally every game of league I play, I cannot send messages to chat or even receive any myself. This happens in pre-made lobbies team select and even in the end-game chat. This is beyond frustrating and really gets me into trouble as I cannot communicate with my team which leads to poor selection of champs and lane positioning. How am I supposed to know which champ to pick or which lane to go to!? SERIOUSLY! This leads me to getting flamed and possibly reported, and even with the new dynamic queue; I got flamed at for not realizing that i picked bot but was put top lane. So when I was picking my champ I couldn't see my mistake and got yelled at a result and got blamed for our loss as a result (even though I didn't feed at all and contributed the most that I could). Seriously My client I horribly bugged and I really ruining the fun I have with this game. Somebody please help, I tried repairing my client and everything. There has to be a solution or something?!