any rockwool fibreglass contains chemicals etc to make it fire resisted and mold resistant - it basically derived from insulation foam used in roofing/building trade- seriously i would not smoke it - who knows what poisons are in that shit, even if you separate who knows what been absorbed into the weed
seriously i would get your money back. if this guy is selling you bullshit he probably thinks your some dumb kid. if you cant whoop his ass toss it and learn from your mistakes.
Lesson learned.