...if my account gets banned I should get all the money I've spent on this game back right?
Nope. You gave your money to Riot Games in a non-refundable transaction - it says so on the backs of Pre-Paid Riot Point cards, and it says so in the in-Client shop when you go to purchase Riot Points. Once you make the trade of your local currency (in this case, USD) for Riot Points, the transaction is done, and the USD you spent belongs to Riot. There is no legal way to get that money back.
Almost like theft honestly.
Theft implies they took the money from you without your consent. You gave them your money, ergo, it's not theft.
If you pay for a good, its your property, meaning you should either get to keep it, or get a refund.
As mentioned earlier, the transaction is non-refundable, but to address the "it's your property" thing, here's a snippet from the Terms of Use:
3.2. Can I do stuff with Riot’s intellectual property? (We reserve all the rights to our IP, but do allow for some personal, non-commercial uses like fan art.)
We (and our licensors) own and reserve all rights and title in and to the Riot Services, and all data and content included therein, including, user accounts, computer code, titles, objects, artifacts, characters, character names, chat logs, Game recordings and broadcasts, locations, location names, stories, dialog, catch phrases, artwork, graphics, structural or landscape designs, animations, sounds, musical compositions and recordings, Riot Points (defined below), Blue Essence (defined below), Hextech Items (defined below), Virtual Goods (defined below), audio-visual effects, character likenesses, methods of operation and gameplay (collectively, “Game Content”).
According to the League of Legends Terms of Use, Section 3, Article 2, Riot has sole ownership of any and all properties in their game, including the Summoner Name you take out onto the fields of battle, the Champions they created, and the skins you bought to wear on them.
In other words, it's not your property, and you didn't buy the item itself. You bought a revocable license to use that item for as long as Riot allows.
...weather(sic) its from false reporting which is a serious issue right now...
False reports won't result in a punishment. It isn't an issue.