Bot Spam Accounts Bugging Out

So this morning I got a request from an account with a name full of random letters and numbers. This account was obviously a spam account. However, when I tried to decline the friend request it wouldn't let me and continued to pop up. So then I decided to friend them and quickly unadd them in order to receive spam. Though, when looking at my friends like, this unknown person was not on my friends list. I didn't think much of it at the time. But when i finished one of my games they messaged me. However, their name was not displayed as the long numerical user. Instead, their name was my club tag (MING!) and obviously they sent a link asking me to pay for boosts. I'm telling this because im not sure if this is a bug riot can fix or if I can do anything about. Thanks for listening :D!

Here's a quick picture of a PM the bot sent me: https://gyazo.com/2fabb7598284c8e268ae290156607830