Boosting and Getting boosted

So.. is boosting allowed nowadays or not? I'm asking this since I've got and had several players in my friends list that were literally paying someone higher to play on their accounts and boost them to a higher elo than the one in which they are. And I'm not talking about premades and being carried in a 3+ man premade through ranked. How exactly can I report someone that's being boosted? Especially when that player openly admits in while talking with me? {{sticker:slayer-jinx-unamused}}
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