Misdemeanor (petty theft) charged as felony (burglary)?

i m 18, and live in california. and what i stole were a pair of sneakers from JC Pennys. and i have no previous crimes; first offender. i was caught shoplifting an item worth $50. when i was caught, i asked security what i would be charged for and he said most likely as petty theft(misdemeanor). but when i got my citation ticket, it said burglary(felony). why did it become a felony? what can i do to have it reduced to misdemeanor if that is even possible? and what should i be expecting as punishment? please give me factual answers..no bathmouthing plz