Re: ISIS represents true Islam?
I dont know who is He, however, no one represents Islam except Quran.. human make mistakes (insan ghaltiyon ka putla hai) and a human can only be right only if he/she is talking from the actual context of Quran, but if he/she is wrong according to Quran, then he/she is lying or have no knowledge.. and so, have nothing to do with Islam..
Quran condemns doing zina/sex as well as killing any innocent whether muslim or non-muslim.. so Quran & Islam have nothing to do with whatever any person say or do..
so I think you are misled about Islam.. you need to read Quran to get knowledge about it.. however if you’re a non-believer, then atleast for the sake of humanity, elegance and kindness, stay away from hurting, bad-mouthing or messing with people/religion/beliefs for no reason.. 
or if there is any reason that is making you restless then dont relate people’s mistakes to Islam/Quran or any other religion..
P.S: you seems a non-believer and proving that non-believers are more messy and full of hatred than the people who believes.. 