talk to your school,
i'll be honest with you, i studied in Cordoba, as an exchange student with my U. and i applied late and had to rush to get my visa, medical, apostle seal. blah blah blah, all costing money, at the end the Argentine consulate got my rush visa and gave me a little lecture on how these things take weeks not days on their part.
when i arrived at the university during orientation, they asked everyone for our paperwork, visas, etc.. and one girl said she didn't have time to completely process it.
I said to myself, "oh man, she Fcuked!!, what happens now?" i got to see this. all they told her is that she is fine on a tourist visa and would have to leave and come back every 90 days.
"really??" WTF, i just spent 3 weeks, days off work, running around dropping cash for every little thing and all i could have done i left the country in 90 days. (which we did for school field trips)
that was my first lesson of Argentina 101, on how things work in the country. if you try doing things the right way, it cost you more..
anyways.. i had a blast so just talk to your U and see if the tourist things works or if you can process it while you are down there.. your paying tuition so that goes a long way
saludos Steve