First, let me preface by saying that I'm generally against the idea of repealing correctly-placed permanent bans. I'm not sure why Riot would go back on their word of not repealing permanent bans unless they were placed in error (if they are, anyway), but, y'know.
Instant feedback is too harsh, places punishment after a bad game even though for MOST of the players games they are great and honorable
This is arguable at best. Depending on the tier of punishment, the IFS gives ample time to build up to a punishment, especially early on. If you earn a chat restriction, you either went pretty far off the deep end (getting a chat restriction from one game), or you've had several games of bad behavior that finally caught up to you.
And getting to a permanent ban generally means you've had 35+ games and 14+ days to adjust and reform, and despite at least three warnings, broke down anyway and wound up banned. That's not an issue of the IFS being too harsh, that's an issue of the player in question not taking things seriously.
permabanned accounts owners are not creating new accounts and re-buying old stuff (money slippage)
......That's the point, though. When Riot permanently bans someone, they don't want that player's money. They don't want the player to come back on a new account or buy more content, they want that player gone. Banned players not coming back is a positive, not a negative.
money sensors/algorithms are showing less money earned from ip's/mac addresses that have bans (banned players arent shelling money to replace acct)
I'm not sure how this is different from point 2, but, largely, the same argument applies. Riot doesn't want the business of a player they've had to permanently ban. If the player still spends money and works to replace their account, they didn't get the hint.
...im looking to get my money back from a chargeback and taking my time/money somewhere else
I'm pretty sure that's illegal. You've already spent your money, and Riot's already given you your content, you can't charge it back. That'd be fraud.