Is this in AI games? Because I've never seen a bot in a PvP game, that would be very bad.
I don't want to sound mean at all, but if you're raging and losing AI games then there are some very basic mechanics you are missing, and I say that because I'm pretty sure people here can help you a lot with that. Attitude is super important in this game - we all have terrible games and meet terrible people and this is at the end of the day, the vent thread, so it's fine but I'm trying to get my head around going 0/7 in an AI game and blaming it on someone who is botting or team mates who don't want you farming their lane (where was your lane? where was your cs? how about the jungle?). Maybe we can help you start getting some kills against AIs and then if you do get a 4v5 in an AI game it shouldn't be that big a deal... because if you're going 0/7 and raging in an AI match then PvP matches are going to give you an aneurysm.
As for why Riot can't do anything - the reason that every single games company out there can't do anything. First, the programs are often run undetectable, or can't be detected automatically that easy, that is what these people are trying to create, the invisible bot from the game developers side, so it is a lot of resources and very hard for them to autodetect. What they can do is ban intentional feeders, even if they can't prove botting. So after every game, keep reporting those people for intentional feeding and they WILL get banned if they're just running in and going 0/20 or whatever. Unfortunately you will never see that result. You can also create a support ticket with the details and they can investigate a bot - but it's not really considered a major problem because these accounts are botted to 30 so they can be sold to people not wanting the grind, wanting a smurf, etc. At 30 these botted accounts are then run by real people and so the bots pretty much never affect PvP. Very few people care about AI games that much because you can usually win them 3 or 4v5 anyway, and it's not where people really feel that competitive, since it's just a fairly basic practice mode.
So if you're getting bots in a PvP game then that's really sucky because it's almost impossible to win a 4v5 especially when someone is feeding, but I've played over 1000 pvp games in the last 6 months and I haven't seen any bots so that would be terrible luck to get 3