You remember any high school chemistry, the Hydroxide group written -OH well that's the same -OH in NaOH, soium hydroxide, or LYE! When you allow the -OH to disassociate it becomes chemically active and can burn the living fuck out of sensitive membranes.

Get your money back! If you're not sure, and you have access to testing equipment, put some in water and let it soak for a while then test the pH. If it is higher than like 6, there's a chance there might be a little in it. If it's higher than 7, watch out.

Anyway ammonia has a strong smell. If you don't know what it smells like, go buy some Parson's floor cleaner and take a nice whiff. When your eyes are done getting all watery you will know what to sniff for on your weed.
To confound this, botyris-infested (moldy) bud can start to stink ammonia too.

My 2 cents, adding ANYTHING -water, ammonia, other drugs, whatever- to bud you're selling is MESSED UP. If some dumbass wants to crush up their psych meds and roll a fatty that's their problem. It like defeats the whole idea of weed being a nice gentle natural herb! DUH.