Xbox 360 Disk Help!!!!!!?

so i got ac brotherhood and it got the perfect circle thing. i went to playntrade and they fixed it. its FULLY cleaned up and when i start the session or story mode it says unreadable disk. so what should i do? im not using any S.H.I.T toothpaste so dont even answer me with that. so what should i do? i washed it and wiped it and everything but its not working! plz answer!