Endure crusted to bottom of pool

[boo hoo]

I introduced endure to our pool today and as instructed by the debutant at
our local pool store poured it in across from our skimmer and proceeded to
brush it out. Unfortunately, before I could brush it out, it turned to concrete at the bottom of the pool. I was told it wouldn't hurt our liner so I turned the heater on today and am hoping to proceed into the pool tomorrow. Any suggestions on how to get this endure/cement from the bottom of our 18' above ground pool and off the liner would be greatly appreciated. Of course upon calling the store, they told us we were suppose to gradually introduce it into our pool and that WE should get the hardened chemical out and try to dissolve it in warm H2O, yet no ideas on how to get it out--