Spells: Cannot cancel Sphere of Light

[Asudad]

I casted the Sphere of Light spell one time and it created the ball of light. The problem is I cannot cancel it and create another one. When I die and come back to bind spot, the ball of light is in my inventory and it is also still on my corpse. As a consequence I cannot loot the ball of light from my corpse as I all ready have one and cannot delete the corpse.

I wanted the spell to train in conjuration, but since I cannot cancel the spell I have not been able to train.