Friend request spammers

People keep spamming me friend requests and when I accept they send a msg that has a link saying stuff like get to challenger free or stuff like that and it is getting very annoying. when I log on I usually have at least 4 people trying to friend me and when I press decline they send more friend requests. can someone help me to get these spammers to stop spamming me friend requests or can riot do something about it? I don't think it is just me they are spamming.