ex created a fake profile of me

A couple of days ago I was on Instagram & for some weird reason I decided to look at a acquaintances followers then that's when I saw it. A fake Instagram of me, I tried adding it but it had me blocked so I made a post telling people to report it for me.. I became super suspicious bc that profile had friends of mine + family members of my ex, also his profile was added to it. so I decided to investigate LOL I went on his gf's twitter and find a lot of tweets about me saying stuff like "his ex needs to know her place I'm being way too patient" & "she thinks she can talk crap but she backs down when I confront her" when I've never talked to her, in fact i blocked my ex from everything even his number. I ignored it.. but today I receive a phone call from his gf yelling at me telling me to back off and leave him alone. So I said "I have him blocked off of everything & that fake profile he made of me.. I reported it and made a post of it" so I sent her screenshots and she shuts up. Then my exs starts yelling in the background "you've been trying to sleep with my brother he showed me the messages and you keep bothering him for my number" I'm just sitting here in disbelief over what's going on... I never even talked to him, I blocked his whole family yet he's still trying to drag me back into his life and acuse me of constantly talking to him & begging for him back wth?