K2 Users Spam Help! - How to delete and stop being spammed

Hi there!

I am looking for help in trying to fix a situation where I am getting a ridiculous amount of spam users/bots that are attacking my site through a K2 Module in which I have a place where real members login and look for a partner etc for their sport.

I have tried a numerous amount of solutions to no avail and am looking for someone who may have encountered this problem or has another suggestion to help fix the issue and either add some spam blockers/delete all the spam users that are currently registered on my site?

Location on Page:
http://nsga.com/finder

Any advice?

Thanks in advance.
Jay