Drug dealers aren't really known for customer service so don't take it back to the guy for a refund unless you know him personally. As for the object, it does look like either coke or crack. Just don't go to the guy again.

You have to be careful who you buy shit from because since weed is illegal, its controlled by asshole scum dealers who lace their shit and sell other poison.

Now if you went to Amsterdam to get weed, you wouldn't have to worry about your weed being laced! Legalization works!