Take a look at the rule book pg21 under spellbinding for more information:"(...)If you use a bound incantation or attack spell, it is not discarded after casting. The Spellbind object retains the bound spell so you can use it over and over again in future game rounds. Also, if the spell is countered or canceled it is not discarded and remains bound.(...)"Answering your question: The spell is cancelled but it continues bound to your wand and you can use it again next round.